[PD] changing the color/text of some GUI element on-the-fly

[David Merrill]

Hi all -
I'm designing a perceptual experiment using PD, and I want to have a big 
sign on-screen whose color changes color, and possibly some text changes 
for each trial. Is there some basic GUI object that can do this? (even 
one of those nice big colored "bang" buttons would be fine, for the 
color-changing part, if I could update its color on the fly)
thanks,
David M.