Highlight appropriate cells; Format-conditional formatting-"Cell Value Is"
"less than" "0", then hit the format button and format appropriately.

"John" wrote:

I have a spread sheet containing columns Budget, Expense, Variance and %
Variance in cols A, B, C and D. Col D contains formulas of the form =C10/A10.

What code would I add to color negative percentage cell text red?

Thx for your help, John