How to set background color for application window

[James Cant <jcant head cfa harvard edu>]

I need to know how to set the default background color used by 
applications.  I discovered once how to do this and set it to red and 
now I'd like to reset it; it was cute to discover I could change it but 
the red is annoying.  I can't find how to change it.  I looked under the 
configuration editor and searched for background color but didn't find 
what I needed.  Any suggestions?

Thanks,

jim