The "pepper noise" is esound loading. The color map issue is probably caused by some programs in GNOME eating colors. Try loading xearth w/o GNOME running and see if that helps.
You failed to mention what window manager you are using. it is the window managers job to control the color palette. So you could also try switching window managers. On 13-Nov-98 Daniel Mashao wrote: > How can I solve the problems of colors on my system. I installed gnome and > it always comes up with pepper noise. Apps such as xearth cannot run as > they do not have enough colors. >