I am porting an application from a Sun workstation to use a PC running
Fedora, the application uses overlay drawing. I have a Nvidia 6600
graphics card which supports the Direct Colour visual, the default
visual is True colour according to the output of xdpyinfo. The problem
that I have is that XAlocColorCells does not work with the default
colormap. I need the default colour map to work, so that all other
applications look correct.
XallocColorCells does work if I create my own colormap, and the
overlays do work, trouble is all other colors are a mess.
How do I get to write to the default colormap, so that I can allocate
my overlay colours?. Or how can I change the default visual?. Or how do
I set up the a new colormap that will provide the same colour output as
the default colormap?. I tried XcopycolormapandFree,but i would not
allow me to allocate colour cells to the new map!.

Any help very much appreciated