display-pane background color

I have some text I need to put on a dialog that will be slightly more 
than one line, so I'm using a display-pane. But unlike a title-pane 
which matches the background color of the dialog, a display pane uses a 
white background by default. Is there a way to determine the default 
background dialog color so I can use a display-pane? On the Mac, I can 
just use :background :transparent, but this does not work on Windows.

Thanks

John DeSoi, Ph.D.