How to set wm bg-color as will?

[Benjamin F. Zhou]

Hi,

is there a way to test/set wm's background color as will. instead of having to
choose among White, Wheat, Orchid, Midnightblue, etc. Can I use hex-code 
instead of
name? I don't have a big vocabulary on colors in english. Is there a site on 
this
subject?

thanks
Ben