Why don't fill colors display in cells?

[Jerry]

Colors don't display in body of Office documents - Excel, Powerpoint, Word,
Internet Explorer, like "Pure Black and White" is turned on, but it doesn't
apply.

Fill option achieves nothing.

Color does display to subsequent recipients of email attachment.

 

[Debra Dalgleish]

If the high contrast setting is turned on you won't see the fill colour.
There's information in the following MSKB article:

The fill color, the fill pattern, or the line color of a WordArt or
AutoShape object in an Office document does not change
http://support.microsoft.com/default.aspx?kbid=833258