# Tk_RGBadv.py

# Tk_RGBadv.py

from Tkinter import *

root=Tk()
def cmd(event):
    r=red.get()
    g=green.get()
    b=blue.get()
    zfg='WHITE'
    if (r*1.2)+(g*2.4)+b > 460: zfg='BLACK'
    color='#%02x%02x%02x' % (r,g,b)
    if color <> sample.prev:
        sample.prev=color
        print color
    sample.configure(background=color)
    lb.configure(foreground=zfg)
    for z in lz:
        z.configure(background=color)
#

sample=Frame(root)
sample.pack(fill=BOTH,expand=1)
la=Label(sample,text='')
lb=Label(sample,text='-- SAMPLE --', fg='WHITE')
lc=Label(sample,text='')
lz=la,lb,lc
for z in lz:
    z.pack(fill=BOTH,expand=1)

red= Scale(root,orient='horizontal',label='RED',to=255,length='5c')
red.pack(fill=X)
green= Scale(root,orient='horizontal',label='GREEN',to=255,length='5c')
green.pack(fill=X)
blue= Scale(root,orient='horizontal',label='BLUE',to=255,length='5c')
blue.pack(fill=X)
sample.prev=''
red.configure(command=cmd)
green.configure(command=cmd)
blue.configure(command=cmd)
root.mainloop()