when windows is in safe mode it ONLY runs in 16 colors at the largest resolution_ so you need to get out of safe mode to change anything to do with your display_
why is it running in safe mode is the question you really need an answer to_
if you have recently installed a new piece of hardware that might be causing the problem_ when Win98 boots to safe mode it normally starts with a black & white screen that informs you it wants to start in safe mode but offers you other options_ have you tried switching to the option 'run normally'? the worst it can do is cause your PC to crash and then it will offer you safe mode again when you reboot_
the main point of this answer though is that your problem is NOT screen colours/resolution_ it's why is the PC running in safe mode_ ok? ; )
maik
November 2006