# Tk_xy2rgb.py

# Tk_xy2rgb.py

from Tkinter import *
from ctypes import windll

root = Tk()

def click(event):
    dc = windll.user32.GetDC(0)
    rgb = windll.gdi32.GetPixel(dc,event.x_root,event.y_root)
    r = rgb & 0xff
    g = (rgb >> 8) & 0xff
    b = (rgb >> 16) & 0xff
    print r,g,b

for i in ['red', 'green', 'blue', 'black', 'white']:
    Label(root, width=30, background=i).pack()

root.bind('<Button-1>', click)

root.mainloop()