Create distinct colours

gistfile1.py

#
# Creates a html page with a list of distinct looking colours for graphs, etc.
# Algorithm from: http://martin.ankerl.com/2009/12/09/how-to-create-random-colors-programmatically/
#
# Jonas Pfannschmidt

from colorsys import hsv_to_rgb

golden_ratio_conjugate = 0.618033988749895

# play around with these values to change the colours
h = 0.8
s = 0.7
v= 0.9

def calc_text_color(r, g, b):
    r = r * 256
    g = g * 256
    b = b * 256

    # Counting the perceptive luminance - human eye favors green color... 
    a = 1 - ( 0.299 * r + 0.587 * g + 0.114 * b)/255;

    if (a < 0.5):
        return '#000000'
    else:
        return '#ffffff'

def html_hex(dec):
    return hex(int(dec * 255)).lstrip('0x').zfill(2)

def colour_256(rgb):
    return (int(rgb[0] * 255), int(rgb[1] * 255), int(rgb[2] * 255))

def html_colour(rgb):
    return '#' + html_hex(rgb[0]) + html_hex(rgb[1]) + html_hex(rgb[2])


for i in range(200):
    # h = i / 20.0
    h = h + golden_ratio_conjugate
    h = h % 1

    rgb = hsv_to_rgb(h, s, v)
    # rgb = hsv_to_rgb(0, 1, 1)


    print '<div style="background-color: {}; color: {}; width: 100px">{}<br>{}</div>'.format(html_colour(rgb), calc_text_color(rgb[0], rgb[1], rgb[2]), html_colour(rgb), colour_256(rgb))