A co-worker accidentally changed the color of the text in her formula bar to
red - didn't know how she had done it and couldn't find any way to change
this back to black, despite closing and re-opening Excel and looking through
all the Tools - Options selections. It did, however, reset to black after
her computer was turned off overnight.

Any idea what keystrokes might have turned the formula bar to red
(independent of cell text format)?