Tkinter: Query system preferences colors

[Phlip]

Not Hyp:

When I use a Tkinter ListBox and select an item, the selection
emphasis background color is (for example) dark cyan.

When I use a Gnome app with a list box and select something, the
selection emphasis background color is also dark cyan.

When I use a Kde app with a list box and select something, the
selection emphasis background color is (guess what?) dark cyan.

When I read the Tk source, it sez it is giving the list box a
selection color of #c3c3c3.

When I query the configurations in use for this ListBox (using print
list.configure()), it says it's using #0a5f89, which is dark cyan.

Where is Tk getting this value? I searched all over its source for
something relevant.

How do I query a desktop configuration (under X11, Kde or Gnome, >not<
Windows or Mac) so that list boxes I construct from canvases
seamlessly integrate with library list boxes?

-- 
  Phlip
      http://www.greencheese.org/HoneySatellite
"The ability to quote is a serviceable substitute for wit."  --
Maugham