Added support for 8-bit/256-colors with the cmd2.EightBitFg and cmd2.EightBitBg classes.

Added support for 24-bit/RGB colors with the cmd2.RgbFg and cmd2.RgbBg classes.

Removed dependency on colorama.

Deprecated cmd2.fg. Use cmd2.Fg instead.
Deprecated cmd2.bg. Use cmd2.Bg instead.

Changed type of ansi.allow_style from a string to an ansi.AllowStyle Enum class.
Fixed bug where using choices on a Settable didn't verify that a valid choice had been entered.

1 files changed, 950 insertions, 204 deletions

diff --git a/cmd2/ansi.py b/cmd2/ansi.py
index 32b50697..91188a9c 100644
--- a/cmd2/ansi.py
+++ b/cmd2/ansi.py
@@ -12,165 +12,56 @@ from typing import (
     IO,
     Any,
     List,
-    Union,
+    Optional,
     cast,
 )
 
-import colorama  # type: ignore [import]
-from colorama import (
-    Back,
-    Fore,
-    Style,
-)
-from wcwidth import (  # type: ignore [import]
+from wcwidth import (  # type: ignore[import]
     wcswidth,
 )
 
-# On Windows, filter ANSI escape codes out of text sent to stdout/stderr, and replace them with equivalent Win32 calls
-colorama.init(strip=False)
+#######################################################
+# Common ANSI escape sequence constants
+#######################################################
+CSI = '\033['
+OSC = '\033]'
+BEL = '\a'
 
-# Values for allow_style setting
-STYLE_NEVER = 'Never'
-"""
-Constant for ``cmd2.ansi.allow_style`` to indicate ANSI style sequences should
-be removed from all output.
-"""
-STYLE_TERMINAL = 'Terminal'
-"""
-Constant for ``cmd2.ansi.allow_style`` to indicate ANSI style sequences
-should be removed if the output is not going to the terminal.
-"""
-STYLE_ALWAYS = 'Always'
-"""
-Constant for ``cmd2.ansi.allow_style`` to indicate ANSI style sequences should
-always be output.
-"""
 
-# Controls when ANSI style sequences are allowed in output
-allow_style = STYLE_TERMINAL
-"""When using outside of a cmd2 app, set this variable to one of:
+class AllowStyle(Enum):
+    """Values for ``cmd2.ansi.allow_style``"""
 
-- ``STYLE_NEVER`` - remove ANSI style sequences from all output
-- ``STYLE_TERMINAL`` - remove ANSI style sequences if the output is not going to the terminal
-- ``STYLE_ALWAYS`` - always output ANSI style sequences
+    ALWAYS = 'Always'  # Always output ANSI style sequences
+    NEVER = 'Never'  # Remove ANSI style sequences from all output
+    TERMINAL = 'Terminal'  # Remove ANSI style sequences if the output is not going to the terminal
 
-to control the output of ANSI style sequences by methods in this module.
-
-The default is ``STYLE_TERMINAL``.
-"""
-
-# Regular expression to match ANSI style sequences (including 8-bit and 24-bit colors)
-ANSI_STYLE_RE = re.compile(r'\x1b\[[^m]*m')
-
-
-class ColorBase(Enum):
-    """
-    Base class used for defining color enums. See fg and bg classes for examples.
-
-    Child classes should define enums in the follow structure:
+    def __str__(self) -> str:
+        """Return value instead of enum name for printing in cmd2's set command"""
+        return str(self.value)
 
-        key: color name (e.g. black)
+    def __repr__(self) -> str:
+        """Return quoted value instead of enum description for printing in cmd2's set command"""
+        return repr(self.value)
 
-        value: anything that when cast to a string returns an ANSI sequence
-    """
 
-    def __str__(self) -> str:
-        """
-        Return ANSI color sequence instead of enum name
-        This is helpful when using a ColorBase in an f-string or format() call
-        e.g. my_str = f"{fg.blue}hello{fg.reset}"
-        """
-        return str(self.value)
+# Controls when ANSI style sequences are allowed in output
+allow_style = AllowStyle.TERMINAL
+"""When using outside of a cmd2 app, set this variable to one of:
 
-    def __add__(self, other: Any) -> str:
-        """
-        Support building a color string when self is the left operand
-        e.g. fg.blue + "hello"
-        """
-        return cast(str, str(self) + other)
+- ``AllowStyle.ALWAYS`` - always output ANSI style sequences
+- ``AllowStyle.NEVER`` - remove ANSI style sequences from all output
+- ``AllowStyle.TERMINAL`` - remove ANSI style sequences if the output is not going to the terminal
 
-    def __radd__(self, other: Any) -> str:
-        """
-        Support building a color string when self is the right operand
-        e.g. "hello" + fg.reset
-        """
-        return cast(str, other + str(self))
+to control how ANSI style sequences are handled by ``style_aware_write()``.
 
-    @classmethod
-    def colors(cls) -> List[str]:
-        """Return a list of color names."""
-        # Use __members__ to ensure we get all key names, including those which are aliased
-        return [color for color in cls.__members__]
+``style_aware_write()`` is called by cmd2 methods like ``poutput()``, ``perror()``,
+``pwarning()``, etc.
 
+The default is ``AllowStyle.TERMINAL``.
+"""
 
-# Foreground colors
-# noinspection PyPep8Naming
-class fg(ColorBase):
-    """Enum class for foreground colors"""
-
-    black = Fore.BLACK
-    red = Fore.RED
-    green = Fore.GREEN
-    yellow = Fore.YELLOW
-    blue = Fore.BLUE
-    magenta = Fore.MAGENTA
-    cyan = Fore.CYAN
-    white = Fore.WHITE
-    bright_black = Fore.LIGHTBLACK_EX
-    bright_red = Fore.LIGHTRED_EX
-    bright_green = Fore.LIGHTGREEN_EX
-    bright_yellow = Fore.LIGHTYELLOW_EX
-    bright_blue = Fore.LIGHTBLUE_EX
-    bright_magenta = Fore.LIGHTMAGENTA_EX
-    bright_cyan = Fore.LIGHTCYAN_EX
-    bright_white = Fore.LIGHTWHITE_EX
-    reset = Fore.RESET
-
-
-# Background colors
-# noinspection PyPep8Naming
-class bg(ColorBase):
-    """Enum class for background colors"""
-
-    black = Back.BLACK
-    red = Back.RED
-    green = Back.GREEN
-    yellow = Back.YELLOW
-    blue = Back.BLUE
-    magenta = Back.MAGENTA
-    cyan = Back.CYAN
-    white = Back.WHITE
-    bright_black = Back.LIGHTBLACK_EX
-    bright_red = Back.LIGHTRED_EX
-    bright_green = Back.LIGHTGREEN_EX
-    bright_yellow = Back.LIGHTYELLOW_EX
-    bright_blue = Back.LIGHTBLUE_EX
-    bright_magenta = Back.LIGHTMAGENTA_EX
-    bright_cyan = Back.LIGHTCYAN_EX
-    bright_white = Back.LIGHTWHITE_EX
-    reset = Back.RESET
-
-
-FG_RESET = fg.reset.value
-"""ANSI sequence to reset the foreground attributes"""
-BG_RESET = bg.reset.value
-"""ANSI sequence to reset the terminal background attributes"""
-RESET_ALL = Style.RESET_ALL
-"""ANSI sequence to reset all terminal attributes"""
-
-# Text intensities
-INTENSITY_BRIGHT = Style.BRIGHT
-"""ANSI sequence to make the text bright"""
-INTENSITY_DIM = Style.DIM
-"""ANSI sequence to make the text dim"""
-INTENSITY_NORMAL = Style.NORMAL
-"""ANSI sequence to make the text normal"""
-
-# ANSI style sequences not provided by colorama
-UNDERLINE_ENABLE = colorama.ansi.code_to_chars(4)
-"""ANSI sequence to turn on underline"""
-UNDERLINE_DISABLE = colorama.ansi.code_to_chars(24)
-"""ANSI sequence to turn off underline"""
+# Regular expression to match ANSI style sequences (including 8-bit and 24-bit colors)
+ANSI_STYLE_RE = re.compile(r'\x1b\[[^m]*m')
 
 
 def strip_style(text: str) -> str:
@@ -225,56 +116,843 @@ def style_aware_write(fileobj: IO[str], msg: str) -> None:
     :param fileobj: the file object being written to
     :param msg: the string being written
     """
-    if allow_style.lower() == STYLE_NEVER.lower() or (allow_style.lower() == STYLE_TERMINAL.lower() and not fileobj.isatty()):
+    if allow_style == AllowStyle.NEVER or (allow_style == AllowStyle.TERMINAL and not fileobj.isatty()):
         msg = strip_style(msg)
     fileobj.write(msg)
 
 
-def fg_lookup(fg_name: Union[str, fg]) -> str:
+####################################################################################
+# Utility functions which create various ANSI sequences
+####################################################################################
+def set_title(title: str) -> str:
     """
-    Look up ANSI escape codes based on foreground color name.
+    Generate a string that, when printed, sets a terminal's window title.
 
-    :param fg_name: foreground color name or enum to look up ANSI escape code(s) for
-    :return: ANSI escape code(s) associated with this color
-    :raises: ValueError: if the color cannot be found
+    :param title: new title for the window
+    :return: the set title string
     """
-    if isinstance(fg_name, fg):
-        return str(fg_name.value)
+    return f"{OSC}2;{title}{BEL}"
 
-    try:
-        ansi_escape = fg[fg_name.lower()].value
-    except KeyError:
-        raise ValueError(f"Foreground color '{fg_name}' does not exist; must be one of: {fg.colors()}")
-    return str(ansi_escape)
+
+def clear_screen(clear_type: int = 2) -> str:
+    """
+    Generate a string that, when printed, clears a terminal screen based on value of clear_type.
+
+    :param clear_type: integer which specifies how to clear the screen (Defaults to 2)
+                       Possible values:
+                       0 - clear from cursor to end of screen
+                       1 - clear from cursor to beginning of the screen
+                       2 - clear entire screen
+                       3 - clear entire screen and delete all lines saved in the scrollback buffer
+    :return: the clear screen string
+    :raises: ValueError if clear_type is not a valid value
+    """
+    if 0 <= clear_type <= 3:
+        return f"{CSI}{clear_type}J"
+    raise ValueError("clear_type must in an integer from 0 to 3")
 
 
-def bg_lookup(bg_name: Union[str, bg]) -> str:
+def clear_line(clear_type: int = 2) -> str:
+    """
+    Generate a string that, when printed, clears a line based on value of clear_type.
+
+    :param clear_type: integer which specifies how to clear the line (Defaults to 2)
+                       Possible values:
+                       0 - clear from cursor to the end of the line
+                       1 - clear from cursor to beginning of the line
+                       2 - clear entire line
+    :return: the clear line string
+    :raises: ValueError if clear_type is not a valid value
     """
-    Look up ANSI escape codes based on background color name.
+    if 0 <= clear_type <= 2:
+        return f"{CSI}{clear_type}K"
+    raise ValueError("clear_type must in an integer from 0 to 2")
 
-    :param bg_name: background color name or enum to look up ANSI escape code(s) for
-    :return: ANSI escape code(s) associated with this color
-    :raises: ValueError: if the color cannot be found
+
+####################################################################################
+# Base classes which are not intended to be used directly
+####################################################################################
+class AnsiSequence:
+    """Base class to create ANSI sequence strings"""
+
+    def __add__(self, other: Any) -> str:
+        """
+        Support building an ANSI sequence string when self is the left operand
+        e.g. Fg.LIGHT_MAGENTA + "hello"
+        """
+        return str(self) + str(other)
+
+    def __radd__(self, other: Any) -> str:
+        """
+        Support building an ANSI sequence string when self is the right operand
+        e.g. "hello" + Fg.RESET
+        """
+        return str(other) + str(self)
+
+
+class FgColor(AnsiSequence):
+    """Base class for ANSI Sequences which set foreground text color"""
+
+    pass
+
+
+class BgColor(AnsiSequence):
+    """Base class for ANSI Sequences which set background text color"""
+
+    pass
+
+
+####################################################################################
+# Implementations intended for direct use
+####################################################################################
+# noinspection PyPep8Naming
+class Cursor:
+    """Create ANSI sequences to alter the cursor position"""
+
+    @staticmethod
+    def UP(count: int = 1) -> str:
+        """Move the cursor up a specified amount of lines (Defaults to 1)"""
+        return f"{CSI}{count}A"
+
+    @staticmethod
+    def DOWN(count: int = 1) -> str:
+        """Move the cursor down a specified amount of lines (Defaults to 1)"""
+        return f"{CSI}{count}B"
+
+    @staticmethod
+    def FORWARD(count: int = 1) -> str:
+        """Move the cursor forward a specified amount of lines (Defaults to 1)"""
+        return f"{CSI}{count}C"
+
+    @staticmethod
+    def BACK(count: int = 1) -> str:
+        """Move the cursor back a specified amount of lines (Defaults to 1)"""
+        return f"{CSI}{count}D"
+
+    @staticmethod
+    def SET_POS(x: int, y: int) -> str:
+        """Set the cursor position to coordinates which are 1-based"""
+        return f"{CSI}{y};{x}H"
+
+
+class TextStyle(AnsiSequence, Enum):
+    """Create text style ANSI sequences"""
+
+    # Resets all styles and colors of text
+    RESET_ALL = 0
+
+    INTENSITY_BOLD = 1
+    INTENSITY_DIM = 2
+    INTENSITY_NORMAL = 22
+
+    ITALIC_ENABLE = 3
+    ITALIC_DISABLE = 23
+
+    OVERLINE_ENABLE = 53
+    OVERLINE_DISABLE = 55
+
+    STRIKETHROUGH_ENABLE = 9
+    STRIKETHROUGH_DISABLE = 29
+
+    UNDERLINE_ENABLE = 4
+    UNDERLINE_DISABLE = 24
+
+    def __str__(self) -> str:
+        """
+        Return ANSI text style sequence instead of enum name
+        This is helpful when using a TextStyle in an f-string or format() call
+        e.g. my_str = f"{TextStyle.UNDERLINE_ENABLE}hello{TextStyle.UNDERLINE_DISABLE}"
+        """
+        return f"{CSI}{self.value}m"
+
+
+class Fg(FgColor, Enum):
+    """
+    Create ANSI sequences for the 16 standard terminal foreground text colors.
+    A terminal's color settings affect how these colors appear.
+    To reset any foreground color, use Fg.RESET.
     """
-    if isinstance(bg_name, bg):
-        return str(bg_name.value)
 
-    try:
-        ansi_escape = bg[bg_name.lower()].value
-    except KeyError:
-        raise ValueError(f"Background color '{bg_name}' does not exist; must be one of: {bg.colors()}")
-    return str(ansi_escape)
+    BLACK = 30
+    RED = 31
+    GREEN = 32
+    YELLOW = 33
+    BLUE = 34
+    MAGENTA = 35
+    CYAN = 36
+    LIGHT_GRAY = 37
+    DARK_GRAY = 90
+    LIGHT_RED = 91
+    LIGHT_GREEN = 92
+    LIGHT_YELLOW = 93
+    LIGHT_BLUE = 94
+    LIGHT_MAGENTA = 95
+    LIGHT_CYAN = 96
+    WHITE = 97
+
+    RESET = 39
 
+    def __str__(self) -> str:
+        """
+        Return ANSI color sequence instead of enum name
+        This is helpful when using an Fg in an f-string or format() call
+        e.g. my_str = f"{Fg.BLUE}hello{Fg.RESET}"
+        """
+        return f"{CSI}{self.value}m"
+
+
+class Bg(BgColor, Enum):
+    """
+    Create ANSI sequences for the 16 standard terminal background text colors.
+    A terminal's color settings affect how these colors appear.
+    To reset any background color, use Bg.RESET.
+    """
+
+    BLACK = 40
+    RED = 41
+    GREEN = 42
+    YELLOW = 44
+    BLUE = 44
+    MAGENTA = 45
+    CYAN = 46
+    LIGHT_GRAY = 47
+    DARK_GRAY = 100
+    LIGHT_RED = 101
+    LIGHT_GREEN = 102
+    LIGHT_YELLOW = 103
+    LIGHT_BLUE = 104
+    LIGHT_MAGENTA = 105
+    LIGHT_CYAN = 106
+    WHITE = 107
+
+    RESET = 49
+
+    def __str__(self) -> str:
+        """
+        Return ANSI color sequence instead of enum name
+        This is helpful when using a Bg in an f-string or format() call
+        e.g. my_str = f"{Bg.BLACK}hello{Bg.RESET}"
+        """
+        return f"{CSI}{self.value}m"
+
+
+class EightBitFg(FgColor, Enum):
+    """
+    Create ANSI sequences for 8-bit terminal foreground text colors. Most terminals support 8-bit/256-color mode.
+    The first 16 colors correspond to the 16 colors from Fg and behave the same way.
+    To reset any foreground color, including 8-bit, use Fg.RESET.
+    """
+
+    BLACK = 0
+    RED = 1
+    GREEN = 2
+    YELLOW = 3
+    BLUE = 4
+    MAGENTA = 5
+    CYAN = 6
+    LIGHT_GRAY = 7
+    DARK_GRAY = 8
+    LIGHT_RED = 9
+    LIGHT_GREEN = 10
+    LIGHT_YELLOW = 11
+    LIGHT_BLUE = 12
+    LIGHT_MAGENTA = 13
+    LIGHT_CYAN = 14
+    WHITE = 15
+    GRAY_0 = 16
+    NAVY_BLUE = 17
+    DARK_BLUE = 18
+    BLUE_3A = 19
+    BLUE_3B = 20
+    BLUE_1 = 21
+    DARK_GREEN = 22
+    DEEP_SKY_BLUE_4A = 23
+    DEEP_SKY_BLUE_4B = 24
+    DEEP_SKY_BLUE_4C = 25
+    DODGER_BLUE_3 = 26
+    DODGER_BLUE_2 = 27
+    GREEN_4 = 28
+    SPRING_GREEN_4 = 29
+    TURQUOISE_4 = 30
+    DEEP_SKY_BLUE_3A = 31
+    DEEP_SKY_BLUE_3B = 32
+    DODGER_BLUE_1 = 33
+    GREEN_3A = 34
+    SPRING_GREEN_3A = 35
+    DARK_CYAN = 36
+    LIGHT_SEA_GREEN = 37
+    DEEP_SKY_BLUE_2 = 38
+    DEEP_SKY_BLUE_1 = 39
+    GREEN_3B = 40
+    SPRING_GREEN_3B = 41
+    SPRING_GREEN_2A = 42
+    CYAN_3 = 43
+    DARK_TURQUOISE = 44
+    TURQUOISE_2 = 45
+    GREEN_1 = 46
+    SPRING_GREEN_2B = 47
+    SPRING_GREEN_1 = 48
+    MEDIUM_SPRING_GREEN = 49
+    CYAN_2 = 50
+    CYAN_1 = 51
+    DARK_RED_1 = 52
+    DEEP_PINK_4A = 53
+    PURPLE_4A = 54
+    PURPLE_4B = 55
+    PURPLE_3 = 56
+    BLUE_VIOLET = 57
+    ORANGE_4A = 58
+    GRAY_37 = 59
+    MEDIUM_PURPLE_4 = 60
+    SLATE_BLUE_3A = 61
+    SLATE_BLUE_3B = 62
+    ROYAL_BLUE_1 = 63
+    CHARTREUSE_4 = 64
+    DARK_SEA_GREEN_4A = 65
+    PALE_TURQUOISE_4 = 66
+    STEEL_BLUE = 67
+    STEEL_BLUE_3 = 68
+    CORNFLOWER_BLUE = 69
+    CHARTREUSE_3A = 70
+    DARK_SEA_GREEN_4B = 71
+    CADET_BLUE_2 = 72
+    CADET_BLUE_1 = 73
+    SKY_BLUE_3 = 74
+    STEEL_BLUE_1A = 75
+    CHARTREUSE_3B = 76
+    PALE_GREEN_3A = 77
+    SEA_GREEN_3 = 78
+    AQUAMARINE_3 = 79
+    MEDIUM_TURQUOISE = 80
+    STEEL_BLUE_1B = 81
+    CHARTREUSE_2A = 82
+    SEA_GREEN_2 = 83
+    SEA_GREEN_1A = 84
+    SEA_GREEN_1B = 85
+    AQUAMARINE_1A = 86
+    DARK_SLATE_GRAY_2 = 87
+    DARK_RED_2 = 88
+    DEEP_PINK_4B = 89
+    DARK_MAGENTA_1 = 90
+    DARK_MAGENTA_2 = 91
+    DARK_VIOLET_1A = 92
+    PURPLE_1A = 93
+    ORANGE_4B = 94
+    LIGHT_PINK_4 = 95
+    PLUM_4 = 96
+    MEDIUM_PURPLE_3A = 97
+    MEDIUM_PURPLE_3B = 98
+    SLATE_BLUE_1 = 99
+    YELLOW_4A = 100
+    WHEAT_4 = 101
+    GRAY_53 = 102
+    LIGHT_SLATE_GRAY = 103
+    MEDIUM_PURPLE = 104
+    LIGHT_SLATE_BLUE = 105
+    YELLOW_4B = 106
+    DARK_OLIVE_GREEN_3A = 107
+    DARK_GREEN_SEA = 108
+    LIGHT_SKY_BLUE_3A = 109
+    LIGHT_SKY_BLUE_3B = 110
+    SKY_BLUE_2 = 111
+    CHARTREUSE_2B = 112
+    DARK_OLIVE_GREEN_3B = 113
+    PALE_GREEN_3B = 114
+    DARK_SEA_GREEN_3A = 115
+    DARK_SLATE_GRAY_3 = 116
+    SKY_BLUE_1 = 117
+    CHARTREUSE_1 = 118
+    LIGHT_GREEN_2 = 119
+    LIGHT_GREEN_3 = 120
+    PALE_GREEN_1A = 121
+    AQUAMARINE_1B = 122
+    DARK_SLATE_GRAY_1 = 123
+    RED_3A = 124
+    DEEP_PINK_4C = 125
+    MEDIUM_VIOLET_RED = 126
+    MAGENTA_3A = 127
+    DARK_VIOLET_1B = 128
+    PURPLE_1B = 129
+    DARK_ORANGE_3A = 130
+    INDIAN_RED_1A = 131
+    HOT_PINK_3A = 132
+    MEDIUM_ORCHID_3 = 133
+    MEDIUM_ORCHID = 134
+    MEDIUM_PURPLE_2A = 135
+    DARK_GOLDENROD = 136
+    LIGHT_SALMON_3A = 137
+    ROSY_BROWN = 138
+    GRAY_63 = 139
+    MEDIUM_PURPLE_2B = 140
+    MEDIUM_PURPLE_1 = 141
+    GOLD_3A = 142
+    DARK_KHAKI = 143
+    NAVAJO_WHITE_3 = 144
+    GRAY_69 = 145
+    LIGHT_STEEL_BLUE_3 = 146
+    LIGHT_STEEL_BLUE = 147
+    YELLOW_3A = 148
+    DARK_OLIVE_GREEN_3 = 149
+    DARK_SEA_GREEN_3B = 150
+    DARK_SEA_GREEN_2 = 151
+    LIGHT_CYAN_3 = 152
+    LIGHT_SKY_BLUE_1 = 153
+    GREEN_YELLOW = 154
+    DARK_OLIVE_GREEN_2 = 155
+    PALE_GREEN_1B = 156
+    DARK_SEA_GREEN_5B = 157
+    DARK_SEA_GREEN_5A = 158
+    PALE_TURQUOISE_1 = 159
+    RED_3B = 160
+    DEEP_PINK_3A = 161
+    DEEP_PINK_3B = 162
+    MAGENTA_3B = 163
+    MAGENTA_3C = 164
+    MAGENTA_2A = 165
+    DARK_ORANGE_3B = 166
+    INDIAN_RED_1B = 167
+    HOT_PINK_3B = 168
+    HOT_PINK_2 = 169
+    ORCHID = 170
+    MEDIUM_ORCHID_1A = 171
+    ORANGE_3 = 172
+    LIGHT_SALMON_3B = 173
+    LIGHT_PINK_3 = 174
+    PINK_3 = 175
+    PLUM_3 = 176
+    VIOLET = 177
+    GOLD_3B = 178
+    LIGHT_GOLDENROD_3 = 179
+    TAN = 180
+    MISTY_ROSE_3 = 181
+    THISTLE_3 = 182
+    PLUM_2 = 183
+    YELLOW_3B = 184
+    KHAKI_3 = 185
+    LIGHT_GOLDENROD_2A = 186
+    LIGHT_YELLOW_3 = 187
+    GRAY_84 = 188
+    LIGHT_STEEL_BLUE_1 = 189
+    YELLOW_2 = 190
+    DARK_OLIVE_GREEN_1A = 191
+    DARK_OLIVE_GREEN_1B = 192
+    DARK_SEA_GREEN_1 = 193
+    HONEYDEW_2 = 194
+    LIGHT_CYAN_1 = 195
+    RED_1 = 196
+    DEEP_PINK_2 = 197
+    DEEP_PINK_1A = 198
+    DEEP_PINK_1B = 199
+    MAGENTA_2B = 200
+    MAGENTA_1 = 201
+    ORANGE_RED_1 = 202
+    INDIAN_RED_1C = 203
+    INDIAN_RED_1D = 204
+    HOT_PINK_1A = 205
+    HOT_PINK_1B = 206
+    MEDIUM_ORCHID_1B = 207
+    DARK_ORANGE = 208
+    SALMON_1 = 209
+    LIGHT_CORAL = 210
+    PALE_VIOLET_RED_1 = 211
+    ORCHID_2 = 212
+    ORCHID_1 = 213
+    ORANGE_1 = 214
+    SANDY_BROWN = 215
+    LIGHT_SALMON_1 = 216
+    LIGHT_PINK_1 = 217
+    PINK_1 = 218
+    PLUM_1 = 219
+    GOLD_1 = 220
+    LIGHT_GOLDENROD_2B = 221
+    LIGHT_GOLDENROD_2C = 222
+    NAVAJO_WHITE_1 = 223
+    MISTY_ROSE1 = 224
+    THISTLE_1 = 225
+    YELLOW_1 = 226
+    LIGHT_GOLDENROD_1 = 227
+    KHAKI_1 = 228
+    WHEAT_1 = 229
+    CORNSILK_1 = 230
+    GRAY_100 = 231
+    GRAY_3 = 232
+    GRAY_7 = 233
+    GRAY_11 = 234
+    GRAY_15 = 235
+    GRAY_19 = 236
+    GRAY_23 = 237
+    GRAY_27 = 238
+    GRAY_30 = 239
+    GRAY_35 = 240
+    GRAY_39 = 241
+    GRAY_42 = 242
+    GRAY_46 = 243
+    GRAY_50 = 244
+    GRAY_54 = 245
+    GRAY_58 = 246
+    GRAY_62 = 247
+    GRAY_66 = 248
+    GRAY_70 = 249
+    GRAY_74 = 250
+    GRAY_78 = 251
+    GRAY_82 = 252
+    GRAY_85 = 253
+    GRAY_89 = 254
+    GRAY_93 = 255
+
+    def __str__(self) -> str:
+        """
+        Return ANSI color sequence instead of enum name
+        This is helpful when using an EightBitFg in an f-string or format() call
+        e.g. my_str = f"{EightBitFg.SLATE_BLUE_1}hello{Fg.RESET}"
+        """
+        return f"{CSI}{38};5;{self.value}m"
+
+
+class EightBitBg(BgColor, Enum):
+    """
+    Create ANSI sequences for 8-bit terminal background text colors. Most terminals support 8-bit/256-color mode.
+    The first 16 colors correspond to the 16 colors from Bg and behave the same way.
+    To reset any background color, including 8-bit, use Bg.RESET.
+    """
+
+    BLACK = 0
+    RED = 1
+    GREEN = 2
+    YELLOW = 3
+    BLUE = 4
+    MAGENTA = 5
+    CYAN = 6
+    LIGHT_GRAY = 7
+    DARK_GRAY = 8
+    LIGHT_RED = 9
+    LIGHT_GREEN = 10
+    LIGHT_YELLOW = 11
+    LIGHT_BLUE = 12
+    LIGHT_MAGENTA = 13
+    LIGHT_CYAN = 14
+    WHITE = 15
+    GRAY_0 = 16
+    NAVY_BLUE = 17
+    DARK_BLUE = 18
+    BLUE_3A = 19
+    BLUE_3B = 20
+    BLUE_1 = 21
+    DARK_GREEN = 22
+    DEEP_SKY_BLUE_4A = 23
+    DEEP_SKY_BLUE_4B = 24
+    DEEP_SKY_BLUE_4C = 25
+    DODGER_BLUE_3 = 26
+    DODGER_BLUE_2 = 27
+    GREEN_4 = 28
+    SPRING_GREEN_4 = 29
+    TURQUOISE_4 = 30
+    DEEP_SKY_BLUE_3A = 31
+    DEEP_SKY_BLUE_3B = 32
+    DODGER_BLUE_1 = 33
+    GREEN_3A = 34
+    SPRING_GREEN_3A = 35
+    DARK_CYAN = 36
+    LIGHT_SEA_GREEN = 37
+    DEEP_SKY_BLUE_2 = 38
+    DEEP_SKY_BLUE_1 = 39
+    GREEN_3B = 40
+    SPRING_GREEN_3B = 41
+    SPRING_GREEN_2A = 42
+    CYAN_3 = 43
+    DARK_TURQUOISE = 44
+    TURQUOISE_2 = 45
+    GREEN_1 = 46
+    SPRING_GREEN_2B = 47
+    SPRING_GREEN_1 = 48
+    MEDIUM_SPRING_GREEN = 49
+    CYAN_2 = 50
+    CYAN_1 = 51
+    DARK_RED_1 = 52
+    DEEP_PINK_4A = 53
+    PURPLE_4A = 54
+    PURPLE_4B = 55
+    PURPLE_3 = 56
+    BLUE_VIOLET = 57
+    ORANGE_4A = 58
+    GRAY_37 = 59
+    MEDIUM_PURPLE_4 = 60
+    SLATE_BLUE_3A = 61
+    SLATE_BLUE_3B = 62
+    ROYAL_BLUE_1 = 63
+    CHARTREUSE_4 = 64
+    DARK_SEA_GREEN_4A = 65
+    PALE_TURQUOISE_4 = 66
+    STEEL_BLUE = 67
+    STEEL_BLUE_3 = 68
+    CORNFLOWER_BLUE = 69
+    CHARTREUSE_3A = 70
+    DARK_SEA_GREEN_4B = 71
+    CADET_BLUE_2 = 72
+    CADET_BLUE_1 = 73
+    SKY_BLUE_3 = 74
+    STEEL_BLUE_1A = 75
+    CHARTREUSE_3B = 76
+    PALE_GREEN_3A = 77
+    SEA_GREEN_3 = 78
+    AQUAMARINE_3 = 79
+    MEDIUM_TURQUOISE = 80
+    STEEL_BLUE_1B = 81
+    CHARTREUSE_2A = 82
+    SEA_GREEN_2 = 83
+    SEA_GREEN_1A = 84
+    SEA_GREEN_1B = 85
+    AQUAMARINE_1A = 86
+    DARK_SLATE_GRAY_2 = 87
+    DARK_RED_2 = 88
+    DEEP_PINK_4B = 89
+    DARK_MAGENTA_1 = 90
+    DARK_MAGENTA_2 = 91
+    DARK_VIOLET_1A = 92
+    PURPLE_1A = 93
+    ORANGE_4B = 94
+    LIGHT_PINK_4 = 95
+    PLUM_4 = 96
+    MEDIUM_PURPLE_3A = 97
+    MEDIUM_PURPLE_3B = 98
+    SLATE_BLUE_1 = 99
+    YELLOW_4A = 100
+    WHEAT_4 = 101
+    GRAY_53 = 102
+    LIGHT_SLATE_GRAY = 103
+    MEDIUM_PURPLE = 104
+    LIGHT_SLATE_BLUE = 105
+    YELLOW_4B = 106
+    DARK_OLIVE_GREEN_3A = 107
+    DARK_GREEN_SEA = 108
+    LIGHT_SKY_BLUE_3A = 109
+    LIGHT_SKY_BLUE_3B = 110
+    SKY_BLUE_2 = 111
+    CHARTREUSE_2B = 112
+    DARK_OLIVE_GREEN_3B = 113
+    PALE_GREEN_3B = 114
+    DARK_SEA_GREEN_3A = 115
+    DARK_SLATE_GRAY_3 = 116
+    SKY_BLUE_1 = 117
+    CHARTREUSE_1 = 118
+    LIGHT_GREEN_2 = 119
+    LIGHT_GREEN_3 = 120
+    PALE_GREEN_1A = 121
+    AQUAMARINE_1B = 122
+    DARK_SLATE_GRAY_1 = 123
+    RED_3A = 124
+    DEEP_PINK_4C = 125
+    MEDIUM_VIOLET_RED = 126
+    MAGENTA_3A = 127
+    DARK_VIOLET_1B = 128
+    PURPLE_1B = 129
+    DARK_ORANGE_3A = 130
+    INDIAN_RED_1A = 131
+    HOT_PINK_3A = 132
+    MEDIUM_ORCHID_3 = 133
+    MEDIUM_ORCHID = 134
+    MEDIUM_PURPLE_2A = 135
+    DARK_GOLDENROD = 136
+    LIGHT_SALMON_3A = 137
+    ROSY_BROWN = 138
+    GRAY_63 = 139
+    MEDIUM_PURPLE_2B = 140
+    MEDIUM_PURPLE_1 = 141
+    GOLD_3A = 142
+    DARK_KHAKI = 143
+    NAVAJO_WHITE_3 = 144
+    GRAY_69 = 145
+    LIGHT_STEEL_BLUE_3 = 146
+    LIGHT_STEEL_BLUE = 147
+    YELLOW_3A = 148
+    DARK_OLIVE_GREEN_3 = 149
+    DARK_SEA_GREEN_3B = 150
+    DARK_SEA_GREEN_2 = 151
+    LIGHT_CYAN_3 = 152
+    LIGHT_SKY_BLUE_1 = 153
+    GREEN_YELLOW = 154
+    DARK_OLIVE_GREEN_2 = 155
+    PALE_GREEN_1B = 156
+    DARK_SEA_GREEN_5B = 157
+    DARK_SEA_GREEN_5A = 158
+    PALE_TURQUOISE_1 = 159
+    RED_3B = 160
+    DEEP_PINK_3A = 161
+    DEEP_PINK_3B = 162
+    MAGENTA_3B = 163
+    MAGENTA_3C = 164
+    MAGENTA_2A = 165
+    DARK_ORANGE_3B = 166
+    INDIAN_RED_1B = 167
+    HOT_PINK_3B = 168
+    HOT_PINK_2 = 169
+    ORCHID = 170
+    MEDIUM_ORCHID_1A = 171
+    ORANGE_3 = 172
+    LIGHT_SALMON_3B = 173
+    LIGHT_PINK_3 = 174
+    PINK_3 = 175
+    PLUM_3 = 176
+    VIOLET = 177
+    GOLD_3B = 178
+    LIGHT_GOLDENROD_3 = 179
+    TAN = 180
+    MISTY_ROSE_3 = 181
+    THISTLE_3 = 182
+    PLUM_2 = 183
+    YELLOW_3B = 184
+    KHAKI_3 = 185
+    LIGHT_GOLDENROD_2A = 186
+    LIGHT_YELLOW_3 = 187
+    GRAY_84 = 188
+    LIGHT_STEEL_BLUE_1 = 189
+    YELLOW_2 = 190
+    DARK_OLIVE_GREEN_1A = 191
+    DARK_OLIVE_GREEN_1B = 192
+    DARK_SEA_GREEN_1 = 193
+    HONEYDEW_2 = 194
+    LIGHT_CYAN_1 = 195
+    RED_1 = 196
+    DEEP_PINK_2 = 197
+    DEEP_PINK_1A = 198
+    DEEP_PINK_1B = 199
+    MAGENTA_2B = 200
+    MAGENTA_1 = 201
+    ORANGE_RED_1 = 202
+    INDIAN_RED_1C = 203
+    INDIAN_RED_1D = 204
+    HOT_PINK_1A = 205
+    HOT_PINK_1B = 206
+    MEDIUM_ORCHID_1B = 207
+    DARK_ORANGE = 208
+    SALMON_1 = 209
+    LIGHT_CORAL = 210
+    PALE_VIOLET_RED_1 = 211
+    ORCHID_2 = 212
+    ORCHID_1 = 213
+    ORANGE_1 = 214
+    SANDY_BROWN = 215
+    LIGHT_SALMON_1 = 216
+    LIGHT_PINK_1 = 217
+    PINK_1 = 218
+    PLUM_1 = 219
+    GOLD_1 = 220
+    LIGHT_GOLDENROD_2B = 221
+    LIGHT_GOLDENROD_2C = 222
+    NAVAJO_WHITE_1 = 223
+    MISTY_ROSE1 = 224
+    THISTLE_1 = 225
+    YELLOW_1 = 226
+    LIGHT_GOLDENROD_1 = 227
+    KHAKI_1 = 228
+    WHEAT_1 = 229
+    CORNSILK_1 = 230
+    GRAY_100 = 231
+    GRAY_3 = 232
+    GRAY_7 = 233
+    GRAY_11 = 234
+    GRAY_15 = 235
+    GRAY_19 = 236
+    GRAY_23 = 237
+    GRAY_27 = 238
+    GRAY_30 = 239
+    GRAY_35 = 240
+    GRAY_39 = 241
+    GRAY_42 = 242
+    GRAY_46 = 243
+    GRAY_50 = 244
+    GRAY_54 = 245
+    GRAY_58 = 246
+    GRAY_62 = 247
+    GRAY_66 = 248
+    GRAY_70 = 249
+    GRAY_74 = 250
+    GRAY_78 = 251
+    GRAY_82 = 252
+    GRAY_85 = 253
+    GRAY_89 = 254
+    GRAY_93 = 255
+
+    def __str__(self) -> str:
+        """
+        Return ANSI color sequence instead of enum name
+        This is helpful when using an EightBitBg in an f-string or format() call
+        e.g. my_str = f"{EightBitBg.KHAKI_3}hello{Bg.RESET}"
+        """
+        return f"{CSI}{48};5;{self.value}m"
+
+
+class RgbFg(FgColor):
+    """
+    Create ANSI sequences for 24-bit (RGB) terminal foreground text colors. The terminal must support 24-bit/true-color mode.
+    To reset any foreground color, including 24-bit, use Fg.RESET.
+    """
+
+    def __init__(self, r: int, g: int, b: int) -> None:
+        """
+        RgbFg initializer
+
+        :param r: integer from 0-255 for the red component of the color
+        :param g: integer from 0-255 for the green component of the color
+        :param b: integer from 0-255 for the blue component of the color
+        :raises: ValueError if r, g, or b is not in the range 0-255
+        """
+        if any(c < 0 or c > 255 for c in [r, g, b]):
+            raise ValueError("RGB values must be integers in the range of 0 to 255")
+
+        self._sequence = f"{CSI}{38};2;{r};{g};{b}m"
+
+    def __str__(self) -> str:
+        """
+        Return ANSI color sequence instead of enum name
+        This is helpful when using an RgbFg in an f-string or format() call
+        e.g. my_str = f"{RgbFg(0, 55, 100)}hello{Fg.RESET}"
+        """
+        return self._sequence
+
+
+class RgbBg(BgColor):
+    """
+    Create ANSI sequences for 24-bit (RGB) terminal background text colors. The terminal must support 24-bit/true-color mode.
+    To reset any background color, including 24-bit, use Bg.RESET.
+    """
+
+    def __init__(self, r: int, g: int, b: int) -> None:
+        """
+        RgbBg initializer
+
+        :param r: integer from 0-255 for the red component of the color
+        :param g: integer from 0-255 for the green component of the color
+        :param b: integer from 0-255 for the blue component of the color
+        :raises: ValueError if r, g, or b is not in the range 0-255
+        """
+        if any(c < 0 or c > 255 for c in [r, g, b]):
+            raise ValueError("RGB values must be integers in the range of 0 to 255")
+
+        self._sequence = f"{CSI}{48};2;{r};{g};{b}m"
+
+    def __str__(self) -> str:
+        """
+        Return ANSI color sequence instead of enum name
+        This is helpful when using an RgbBg in an f-string or format() call
+        e.g. my_str = f"{RgbBg(100, 255, 27)}hello{Bg.RESET}"
+        """
+        return self._sequence
 
+
+# TODO: Remove this PyShadowingNames usage when deprecated fg and bg classes are removed.
 # noinspection PyShadowingNames
 def style(
     text: Any,
     *,
-    fg: Union[str, fg] = '',
-    bg: Union[str, bg] = '',
-    bold: bool = False,
-    dim: bool = False,
-    underline: bool = False,
+    fg: Optional[FgColor] = None,
+    bg: Optional[BgColor] = None,
+    bold: Optional[bool] = None,
+    dim: Optional[bool] = None,
+    italic: Optional[bool] = None,
+    overline: Optional[bool] = None,
+    strikethrough: Optional[bool] = None,
+    underline: Optional[bool] = None,
 ) -> str:
     """
     Apply ANSI colors and/or styles to a string and return it.
@@ -282,59 +960,74 @@ def style(
     to undo whatever styling was done at the beginning.
 
     :param text: text to format (anything convertible to a str)
-    :param fg: foreground color. Relies on `fg_lookup()` to retrieve ANSI escape based on name or enum.
+    :param fg: foreground color provided as any subclass of FgColor (e.g. Fg, EightBitFg, RgbFg)
                Defaults to no color.
-    :param bg: background color. Relies on `bg_lookup()` to retrieve ANSI escape based on name or enum.
+    :param bg: foreground color provided as any subclass of BgColor (e.g. Bg, EightBitBg, RgbBg)
                Defaults to no color.
-    :param bold: apply the bold style if True. Can be combined with dim. Defaults to False.
-    :param dim: apply the dim style if True. Can be combined with bold. Defaults to False.
+    :param bold: apply the bold style if True. Defaults to False.
+    :param dim: apply the dim style if True. Defaults to False.
+    :param italic: apply the italic style if True. Defaults to False.
+    :param overline: apply the overline style if True. Defaults to False.
+    :param strikethrough: apply the strikethrough style if True. Defaults to False.
     :param underline: apply the underline style if True. Defaults to False.
     :return: the stylized string
     """
     # List of strings that add style
-    additions: List[str] = []
+    additions: List[AnsiSequence] = []
 
     # List of strings that remove style
-    removals: List[str] = []
+    removals: List[AnsiSequence] = []
 
     # Convert the text object into a string if it isn't already one
     text_formatted = str(text)
 
     # Process the style settings
-    if fg:
-        additions.append(fg_lookup(fg))
-        removals.append(FG_RESET)
+    if fg is not None:
+        additions.append(fg)
+        removals.append(Fg.RESET)
 
-    if bg:
-        additions.append(bg_lookup(bg))
-        removals.append(BG_RESET)
+    if bg is not None:
+        additions.append(bg)
+        removals.append(Bg.RESET)
 
     if bold:
-        additions.append(INTENSITY_BRIGHT)
-        removals.append(INTENSITY_NORMAL)
+        additions.append(TextStyle.INTENSITY_BOLD)
+        removals.append(TextStyle.INTENSITY_NORMAL)
 
     if dim:
-        additions.append(INTENSITY_DIM)
-        removals.append(INTENSITY_NORMAL)
+        additions.append(TextStyle.INTENSITY_DIM)
+        removals.append(TextStyle.INTENSITY_NORMAL)
+
+    if italic:
+        additions.append(TextStyle.ITALIC_ENABLE)
+        removals.append(TextStyle.ITALIC_DISABLE)
+
+    if overline:
+        additions.append(TextStyle.OVERLINE_ENABLE)
+        removals.append(TextStyle.OVERLINE_DISABLE)
+
+    if strikethrough:
+        additions.append(TextStyle.STRIKETHROUGH_ENABLE)
+        removals.append(TextStyle.STRIKETHROUGH_DISABLE)
 
     if underline:
-        additions.append(UNDERLINE_ENABLE)
-        removals.append(UNDERLINE_DISABLE)
+        additions.append(TextStyle.UNDERLINE_ENABLE)
+        removals.append(TextStyle.UNDERLINE_DISABLE)
 
     # Combine the ANSI style sequences with the text
-    return "".join(additions) + text_formatted + "".join(removals)
+    return "".join(map(str, additions)) + text_formatted + "".join(map(str, removals))
 
 
 # Default styles for printing strings of various types.
 # These can be altered to suit an application's needs and only need to be a
 # function with the following structure: func(str) -> str
-style_success = functools.partial(style, fg=fg.green)
+style_success = functools.partial(style, fg=Fg.GREEN)
 """Partial function supplying arguments to :meth:`cmd2.ansi.style()` which colors text to signify success"""
 
-style_warning = functools.partial(style, fg=fg.bright_yellow)
+style_warning = functools.partial(style, fg=Fg.LIGHT_YELLOW)
 """Partial function supplying arguments to :meth:`cmd2.ansi.style()` which colors text to signify a warning"""
 
-style_error = functools.partial(style, fg=fg.bright_red)
+style_error = functools.partial(style, fg=Fg.LIGHT_RED)
 """Partial function supplying arguments to :meth:`cmd2.ansi.style()` which colors text to signify an error"""
 
 
@@ -348,9 +1041,6 @@ def async_alert_str(*, terminal_columns: int, prompt: str, line: str, cursor_off
     :param alert_msg: the message to display to the user
     :return: the correct string so that the alert message appears to the user to be printed above the current line.
     """
-    from colorama import (
-        Cursor,
-    )
 
     # Split the prompt lines since it can contain newline characters.
     prompt_lines = prompt.splitlines()
@@ -385,20 +1075,76 @@ def async_alert_str(*, terminal_columns: int, prompt: str, line: str, cursor_off
 
     # Clear each line from the bottom up so that the cursor ends up on the first prompt line
     total_lines = num_prompt_terminal_lines + num_input_terminal_lines
-    terminal_str += (colorama.ansi.clear_line() + Cursor.UP(1)) * (total_lines - 1)
+    terminal_str += (clear_line() + Cursor.UP(1)) * (total_lines - 1)
 
     # Clear the first prompt line
-    terminal_str += colorama.ansi.clear_line()
+    terminal_str += clear_line()
 
     # Move the cursor to the beginning of the first prompt line and print the alert
     terminal_str += '\r' + alert_msg
     return terminal_str
 
 
-def set_title_str(title: str) -> str:
-    """Get the required string, including ANSI escape codes, for setting window title for the terminal.
+####################################################################################
+# The following classes are deprecated.
+####################################################################################
+# noinspection PyPep8Naming
+class fg(FgColor, Enum):
+    """Deprecated Enum class for foreground colors. Use Fg instead."""
+
+    black = 30
+    red = 31
+    green = 32
+    yellow = 33
+    blue = 34
+    magenta = 35
+    cyan = 36
+    white = 37
+    reset = 39
+    bright_black = 90
+    bright_red = 91
+    bright_green = 92
+    bright_yellow = 93
+    bright_blue = 94
+    bright_magenta = 95
+    bright_cyan = 96
+    bright_white = 97
 
-    :param title: new title for the window
-    :return: string to write to sys.stderr in order to set the window title to the desired test
-    """
-    return cast(str, colorama.ansi.set_title(title))
+    def __str__(self) -> str:
+        """
+        Return ANSI color sequence instead of enum name
+        This is helpful when using an fg in an f-string or format() call
+        e.g. my_str = f"{fg.blue}hello{fg.reset}"
+        """
+        return f"{CSI}{self.value}m"
+
+
+# noinspection PyPep8Naming
+class bg(BgColor, Enum):
+    """Deprecated Enum class for background colors. Use Bg instead."""
+
+    black = 40
+    red = 41
+    green = 42
+    yellow = 43
+    blue = 44
+    magenta = 45
+    cyan = 46
+    white = 47
+    reset = 49
+    bright_black = 100
+    bright_red = 101
+    bright_green = 102
+    bright_yellow = 103
+    bright_blue = 104
+    bright_magenta = 105
+    bright_cyan = 106
+    bright_white = 107
+
+    def __str__(self) -> str:
+        """
+        Return ANSI color sequence instead of enum name
+        This is helpful when using a bg in an f-string or format() call
+        e.g. my_str = f"{bg.black}hello{bg.reset}"
+        """
+        return f"{CSI}{self.value}m"