gistfile1.pl

#!/usr/bin/perl
# Author: Todd Larason <[email protected]>
# $XFree86: xc/programs/xterm/vttests/256colors2.pl,v 1.2 2002/03/26 01:46:43 dickey Exp $

# use the resources for colors 0-15 - usually more-or-less a
# reproduction of the standard ANSI colors, but possibly more
# pleasing shades

# should look like https://forums.freebsd.org/threads/urxvt-tmux-256-colors.38399/

# colors 16-231 are a 6x6x6 color cube
for ( $red = 0 ; $red < 6 ; $red++ ) {
    for ( $green = 0 ; $green < 6 ; $green++ ) {
        for ( $blue = 0 ; $blue < 6 ; $blue++ ) {
            printf(
                "\x1b]4;%d;rgb:%2.2x/%2.2x/%2.2x\x1b\\",
                16 + ( $red * 36 ) + ( $green * 6 ) + $blue,
                ( $red   ? ( $red * 40 + 55 )   : 0 ),
                ( $green ? ( $green * 40 + 55 ) : 0 ),
                ( $blue  ? ( $blue * 40 + 55 )  : 0 )
            );
        }
    }
}

# colors 232-255 are a grayscale ramp, intentionally leaving out
# black and white
for ( $gray = 0 ; $gray < 24 ; $gray++ ) {
    $level = ( $gray * 10 ) + 8;
    printf( "\x1b]4;%d;rgb:%2.2x/%2.2x/%2.2x\x1b\\", 232 + $gray, $level, $level, $level );
}

# display the colors

# first the system ones:
print "System colors:\n";
for ( $color = 0 ; $color < 8 ; $color++ ) {
    print "\x1b[48;5;${color}m  ";
}
print "\x1b[0m\n";
for ( $color = 8 ; $color < 16 ; $color++ ) {
    print "\x1b[48;5;${color}m  ";
}
print "\x1b[0m\n\n";

# now the color cube
print "Color cube, 6x6x6:\n";
for ( $green = 0 ; $green < 6 ; $green++ ) {
    for ( $red = 0 ; $red < 6 ; $red++ ) {
        for ( $blue = 0 ; $blue < 6 ; $blue++ ) {
            $color = 16 + ( $red * 36 ) + ( $green * 6 ) + $blue;
            print "\x1b[48;5;${color}m  ";
        }
        print "\x1b[0m ";
    }
    print "\n";
}

# now the grayscale ramp
print "Grayscale ramp:\n";
for ( $color = 232 ; $color < 256 ; $color++ ) {
    print "\x1b[48;5;${color}m  ";
}
print "\x1b[0m\n";