> 8 bit. X11 shouldn't really have a problem with this - the graphics
> board in my HP9000/345 does 6bit colour ( but nothing else ), some
> programs found it odd to find 64 colour cells though.

The X11 protocol does impose limits on the bpp of pixmaps -- 1, 8, 16,
24 and 32, IIRC.  For example, NeXT hardware has depth 2 at 2 bpp,
which is exported to clients as depth 2 at 8 bpp, i.e. 8 bits per
pixel with only two bits actually used.  Similarly, X servers for
plain VGA cards use depth 4 at 8 bpp.

Obviously, the repacking of pixmaps isn't free.

                                        Juliusz Chroboczek