Here are a few suggestions that might cure your problem:
- Open the Monitors control panel. Click on the Options button. In the
dialog box which appears, you can set aside more RAM for displaying colors.
Click the button marked: "Up to 256 Colors/Grays" Click the OK button to
return to the Monitors control panel.
- Reset PRAM. Under System 6.0.x, hold down the Command-Option-Shift keys while
selecting the control panel. Click OK. Under System 7.x and Mac OS 8, hold down the
Command, Option, P and R keys while starting up your Macintosh. When the
Macintosh restarts again, release the keys.
- Restart from a System Tools Disk. If you can then select
8-bit color, trash and then reinstall the System Folder on the hard
drive.
- If the above options don't work for you, you may have a problem
with the Macintosh IIsi Logic Board.