I have to run an old application that requires my display to run at 8 bit colors. This application will use a dynamic colormap (using XStoreColors). If my display already uses too many colors, there will not be enough free spaces in the map for the applicatoin (as this is not my application I don't know the details here).Currently we are looking into using a more modern window manager for this application (Gnome 2.28 in this case), instead of Motif Window Manager, which it currently uses. How can I reduce the amount of colors used by Gnome? Looks are not important, a good solution would be if only the colors black and white are used. Also in the start menu only a few (custom) options need to be present, and the task bar can be disabled. So far I have been able to reduce the amount of colors vastly with the following settings (from the appearance settings menu):Use the high contrast controls and icons.Using the window borders theme 'Mist' (this actually still uses some shades).Setting the background to a solid color.Using monochrome font rendering.This still leaves many grayscales (Antialiassing effects) in the icons, but I can disable those. Are there any Gnome themes that do this even better, or settings to improve on this further? 
How do I reduce the amount of colors Gnome uses
gnome;colors;theme