Sounds like Conditional Formatting. Type "Highlight cells that meet specific
conditions" into the Excel help to find out all about it.

"Janet" wrote:

I was working with an old spreadsheet that a previous employee created. When
I enter the new amounts & then tab down to the next cell, a fill applies
itself automatically. I like this feature & would like to apply it to other
financial spreadsheets. After many hours at home trying to figure this out -
I've not found an answer. How is this done?
Thanks so much,
Janet