Xterm 256 Colors

256COLOR • About • Codes • RGB Values • Support • Detection • Links ANSI 256COLOR TRUECOLOR VT100 XTERM

Support for 256 colors was added to xterm in 1999 by its maintainer Thomas Dickey, using a patch created by Todd Larason. It's an extension to the ANSI color standard using a compatible format and has been adopted by most terminal emulators and MUD clients.

To send a 256 color foreground color one must print "\e[38;5;#m" where # is a number between 0 and 255. For background colors one must print "\e[48;5;#m" where # behaves in the same manner as foreground colors.

256 Color Codes

256 Color Escape Sequences

Code Effect Note \e [ CSI Control Sequence Indicator CSI n m ANSICOLOR ANSI color code (Select Graphic Rendition) CSI 38 ; 5 ; n m 256COLOR Foreground 8 bit 256 color code CSI 48 ; 5 ; n m 256COLOR Background 8 bit 256 color code CSI 38 ; 2 ; r ; g ; b m TRUECOLOR Foreground 24 bit rgb color code CSI 48 ; 2 ; r ; g ; b m TRUECOLOR Background 24 bit rgb color code

256 Color Options

Code Effect Note 0-7 8 colors: normal The traditional 8 ANSI colors in normal intensity 8-15 8 colors: bold The traditional 8 ANSI colors in bold intensity 16-231 216 colors: rgb Each RGB color has a value between 0 and 5. Red is multiplied by 36, Green by 6, and Blue by 1. 232-255 24 colors: grayscale 24 shades of gray, not including black and white

256 Color RGB Values

To display code 0 through 15 using 24 bit RGB colors the following hexadecimal values are suggested: \x00 and \xAA for normal intensities, and \x55 and \xxFF for bold intensities.

Name Black Red Green Yellow Blue Magenta Cyan White Code 0 1 2 3 4 5 6 7 Normal 000000 AA0000 00AA00 AAAA00 0000AA AA00AA 00AAAA AAAAAA Code 8 9 10 11 12 13 13 15 Bold 555555 FF5555 55FF55 FFFF55 5555FF FF55FF 55FFFF FFFFFF

To display code 16 through 231 using 24 bit RGB colors the following hexadecimal values are suggested for the 6 intensities on a black background: 00, 66, 88, BB, DD, and FF. The 216 RGB color variants can be separated into three achromatic colors, three primary colors, three secondary colors, and six tertiary colors. In the ANSI tradition these can be split into dim and bold intensities. To calculate the color code multiply the red intensity by 36, the green intensity by 6, the blue intensity by 1, and add 16 for the offset.

Name Code Dim Code Bold Azure 025 0066BB 033 0088FF Blue 019 0000BB 021 0000FF Cyan 037 00BBBB 051 00FFFF Ebony 016 000000 059 666666 Green 034 00BB00 046 00FF00 Jade 035 00BB66 048 00FF88 Lime 070 66BB00 118 88FF00 Magenta 127 BB00BB 201 FF00FF Orange 130 BB6600 208 FF8800 Pink 125 BB0066 198 FF0088 Red 124 BB0000 196 FF0000 Silver 102 888888 188 DDDDDD Tan 094 886600 178 DDBB00 Violet 055 6600BB 093 8800FF White 145 BBBBBB 231 FFFFFF Yellow 142 BBBB00 226 FFFF00

To display code 232 through 255 using 24 bit RGB colors the following hexadecimal values are suggested for the 24 shade grayscale: start out at 8 for the first color and increment the value by 10 for each increment. \x08, \x12, \x1C, \x26, etc.

232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255

Support

256 color support is available in most MUD clients and terminal emulators that were updated after 2008.

Detection

There is no universal standard for the detection or negotiation of 256 color support. The following methods exist:

By using the TTYPE TELNET option and checking for a terminal emulator or mud client known to support 256 colors, such as xterm. By using the TTYPE TELNET option and checking for the -256color, or -truecolor suffix. For example: xterm-256color. By using the TTYPE TELNET option and using the MUD Terminal Type Standard to detect 256 color support.

Links

If you want a link added, you can email me at mudclient@gmail.com.

Clients supporting 256 color

Comparison of MUD clients - Wikipedia has a list of MUD clients with 256 color support.

Comparison of terminal emulators - Wikipedia has a list of terminal emulators with 256 color support.

Codebases

Comparison of MUD codebases - Mudpedia contains a list of MUD servers with 256 color support.

Snippets

256 color parser - Handles ANSI 16 colors and xterm 256 colors.