Change a certain color (RGB) in a GIF file to something else for all files in the directory.

change_color.py

__author__ = 'ender'

import numpy as np
import Image
import os

os.chdir('image_dir')
for file in os.listdir('.'):
    if not file.endswith('.gif'):
        continue

    im = Image.open(file)
    im = im.convert('RGB')
    data = np.array(im)

    r1, g1, b1 = 192, 0, 0 # Original value
    r2, g2, b2 = 30, 138, 203 # Value that we want to replace it with

    red, green, blue = data[:,:,0], data[:,:,1], data[:,:,2]
    mask = (red == r1) & (green == g1) & (blue == b1)
    data[:,:,:3][mask] = [r2, g2, b2]

    im = Image.fromarray(data)
    im.save(file)

Original reference:
http://stackoverflow.com/questions/6483489/change-the-color-of-all-pixels-with-another-color

Changes made for all the files and gif conversion.