While working late on a very large workbook late one night a window popped up
offering a high visability configuration and with beleagured eyeballs I
foolishly decided to try it. Instantly the screen disply went into an
inverted monochrome format (black screen with white text). As much of the
workbook is color-coded this was not a good thing. I have been able to
un-invert the display but it remains in a monochrome form despite the fact
the cell formattting remains intact and prints properly. Other programs work
normally so I it would appear to be an Excel setting but I have been unable
to locate anything that seems to be related and neither Excel or Office
Online help have been able to provide any relevant suggestions.