Subject:   -64- I'm using the GlxMDraw widget and it doesn't seem that
                colors are being installed correctly.  Overlays in the
                GlxMDraw widget are displayed in red and gray instead of
                the colors I specify.  What's wrong?
Date: 10 Jun 1993 00:00:01 EST

  The window manager must be directed to install all appropriate
  colormaps.  Use the XSetWMColormapWindows() call to do this -- list
  one window for each colormap to be installed plus the top level
  window.  If using overlays, include the overlay window as well as the
  normal GL window.

  If your window is TrueColor, you should still install the appropriate
  colormap, as Indigo TrueColor is simulated using a colormap.