
This can be caused by two one of two things.  The first and easiest to fix is
interference from something around the monitor, such as another monitor or
other electrical device.  Try moving the system to another location to fix
that problem.

Second, because of the scan rate of the monitor, it tends to synchronize with
room lights and can cause the interference you are seeing.  Try turning off
all lights in the room(s) around the system and see if that helps.  If not,
try moving the system somewhere else.

A third solution would be to get a 14" Apple Color Display - It should not
have the same problem the 12" Color is more suceptible to.

You can try calling Apple's new support number (in the U.S.) at 1-800-SOS-APPLE.
This number is for ANYONE who has questions regarding Macintosh setup and
compatibility and just went into effect for this extended support on Monday,
April 5, 1993.

Good luck -