$Id$ o Colour does not work with all backends and all terminals. I tested many terminal emulators and tried to summarise which combinations worked properly and which ones did not. From termcap(5): set_a_background setab AB Set background color to #1, using ANSI escape set_a_foreground setaf AF Set foreground color to #1, using ANSI escape From the xterm terminfo: setab=\E[4%p1%dm, setaf=\E[3%p1%dm From the xterm-16color terminfo: (http://www.sct.gu.edu.au/~anthony/info/X/Xterm_xf86.terminfo) setab=\E[%?%p1%{8}%<%t%p1%{40}%+%e%p1%{92}%+%;%dm, setaf=\E[%?%p1%{8}%<%t%p1%{30}%+%e%p1%{82}%+%;%dm, These values can be simply retrieved with a tigetstr() call. o I tested the following terminals: name $TERM $COLORTERM ------------------------------------------ Linux console linux pterm xterm aterm xterm rxvt-xpm wterm xterm wterm-xpm Eterm xterm Eterm xterm xterm gnome-terminal xterm konsole xterm mlterm mlterm uxterm xterm o In most terminals, \e[3xm and \[4xm respectively set the foreground and background colours. x is a colour between 0 and 7 or the value 9 for default colour (may be transparent). \e[0m sets everything to normal, \e[1m sets bold, \e[5m sets blink and \e[7m sets inverse video. In ncurses, only 64 colour pairs are created, and A_BOLD (\e[1m) and A_BLINK (\e[5m) are used for foreground/background colour highlighting, hence creating 256 possible colour pairs. Different tests of blue on yellow: for invert in '' '\e[7m'; do for blink in '' '\e[5m'; do for bold in '' '\e[1m'; do echo -ne "$bold$blink$invert"'\e[33m\e[44m'hop'\e[0m ' echo "($bold$blink$invert)" done done done Successfully works on: + Linux console + pterm + Eterm + aterm, wterm, rxvt Almost works on: + xterm (bright bg only works when fg is bright and then inverted, but then fg is not bright) Fails on: + mlterm (no bright colours, neither fg nor bg) + gnome-terminal (no bright bg) + konsole (no bright bg, $blink really blinks) o In an XTerm-compatible terminal, \e[9xm sets bright foreground and \e[10xm bright background colours. Documentation on this can be found at http://ftp.xfree86.org/pub/XFree86/4.2.1/doc/ctlseqs.TXT . Unfortunately all terminals don't support these escape sequences. Here is a testcase: for fgpre in 3 9; do for fg in 0 4 2 6 1 5 3 7; do for bgpre in 4 10; do echo -ne '\e['$fgpre$fg'm' for bg in 0 4 2 6 1 5 3 7; do echo -ne '\e['$bgpre$bg'm# '; done echo -ne '\e[0m ' done echo '' done; echo ''; done Successfully tested on: + gnome-terminal + konsole + xterm + pterm Failed (\e[9x and \e[10x don't do anything) on: + Eterm + aterm, wterm, rxvt + mlterm + Linux console o How to draw bright colours on any terminal? '\e[93;104m' -> bright yellow on bright blue doesn't work on mlterm, gnome-terminal, konsole '\e[5;1;33;44m' -> bright yellow on bright blue doesn't work on mlterm, aterm/wterm/rxvt, Eterm, console '\e[5;1;33;44;93;104m' -> bright yellow on bright blue works on gnome-terminal, xterm, pterm, aterm/wterm/rxvt, console doesn't work on konsole o S-Lang: 256 character pairs are definable, but only 128 can be used. This is because slsmg.c's This_Color variable uses its 8th bit to indicate an alternate character set. Replacing a few 0x7F with 0xFF in sldisply.c works around the problem but gets rid of the alternate charset. We can work around this problem. See this usage grid: bg 1 1 1 1 1 1 fg 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 0 (black) C C C C C C F B c c c c c c F 1 (blue) A h D h D i f C C h E h E k g 2 (green) A h D h i D f C h C E h k E g 3 (cyan) A D D i h h f C E E C k h h g 4 (red) A h h i D D f C h h k C E E g 5 (magenta) A D i h D h f C E k h E C h g 6 (brown) A i D h D h f C k E h E h C g 7 (light gray) A F a a a a a B C C C C C C B 8 (dark gray) A C C C C C C B d d d d d d F 9 (light blue) A C h E h E j C e h D h D l C 10 (light green) A h C E h j E C e h D h l D C 11 (light cyan) A E E C j h h C e D D l h h C 12 (light red) A h h j C E E C e h h l D D C 13 (light magenta) A E j h E C h C e D l h D h C 14 (yellow) A j E h E h C C e l D h D h C 15 (white) A F b b b b b B F C C C C C C ' ': useless colour pairs that can be emulated by printing a space in any other colour pair that has the same background 'A': black background colour pairs that are needed for the old renderer 'B': gray combinations used for grayscale dithering 'C': white/light, light/dark, lightgray/light, darkgray/dark, dark/black combinations often used for saturation/value dithering (the two other possible combinations, lightgray/dark and darkgray/light, are not considered here) 'D': next colour combinations for hue dithering (magenta/blue, blue/green and so on) 'E': next colour combinations for hue/value dithering (blue/lightgreen, green/lightblue and so on) 'F': black on light gray, black on white, white on dark gray, dark gray on white, white on blue, light gray on blue (chosen arbitrarily) 'A': 15 colour pairs 'A'+'B': 20 colour pairs 'A'+'B'+'C': 74 colour pairs 'A'+'B'+'C'+'D': 98 colour pairs 'A'+'B'+'C'+'D'+'E': 122 colour pairs 'A'+'B'+'C'+'D'+'E'+'F': 128 colour pairs The remaining slightly important colour pairs are: 'a': light gray on dark colour: emulate with light colour on dark colour 'b': white on dark colour: emulate with light gray on light colour 'c': black on light colour: emulate with dark gray on dark colour 'd': dark gray on light colour: emulate with dark colour on light colour 'e': light colour on dark gray: emulate with dark colour on dark gray 'f': dark colour on light gray: emulate with light colour on light gray 'g': dark colour on white: emulate with light colour on white And now the seldom used pairs: 'h': 120 degree hue pairs can be emulated as well; for instance blue on red can be emulated using magenta on red, and blue on green using cyan on green And the almost never used pairs: 'i': dark opposite on dark: emulate with dark opposite on black 'j': light opposite on dark: emulate with light opposite on black 'k': dark opposite on light: emulate with black on dark 'l': light opposite on light: emulate with white on light o MS-DOS: all bright colours, bright backgrounds, and bright combinations work using . No need to kludge anything.