Once every couple of weeks or so (I use excel a lot), for no apparent
reason, all the cell background colours (except white) will shift
slightly. When I open the color palettes, they have changed too.
Closing and reopening Excel tends to help (but not always). I have no
idea what is going on. Hopefully it's something I'm doing and not just
random. I wouldn't mind it so much, but sometimes I get dark text on a
dark bg. For instance, orange will turn brown, light blue turns dark
blue, pale yellow turns bright yellow. Sound familiar to anyone?