show-all-256-colors.py

#!/usr/bin/python

def hrun(start, width, padding=0):
    return [None] * padding + range(start, start+width) + [None] * padding

def vrun(start, width, height, padding=0):
    return [hrun(s, width, padding)
            for s in range(start, start+width*height, width)]

layout = [
    vrun(0, 8, 2),            # 16 standard xterm colors
    vrun(16, 6, 6*6, 1),      # 6x6x6 color cube
    vrun(16 + 6*6*6, 8, 3),   # 24 grey levels
]

def fg_seq(color):
    return '\033[38;5;%dm' % color

def bg_seq(color):
    return '\033[48;5;%dm' % color

reset_seq = '\033[0m'

def color_bar(seq, color, trail):
    if color is None:
        return '%s    %s' % (reset_seq, trail)
    else:
        return '%s %03d%s' % (seq(color), color, trail)


for block in layout:
    print
    for row in block:
        fg_bar = ''.join(color_bar(fg_seq, color, '') for color in row)
        bg_bar = ''.join(color_bar(bg_seq, color, ' ') for color in row)
        print '%s%s    %s%s' % (fg_bar, reset_seq, bg_bar, reset_seq)