Fill color for a cell with a "if statement" formula

[firstWeMeet]

P31=IF(SUM(Table1[Total])=0,"",SUM(Table1[Total]))

I shade RED the P31 using fill color then I would like the P31 will be white color if the SUM total is Greater than -0 or 0.
ANyone can help me here? thanks

 

[VoG]

Try using Conditional Formatting to create the fill colour http://www.contextures.com/xlCondFormat01.html

 

[firstWeMeet]

I just wondering because I already using conditional formatting but its not working since my cell containing the formula above.

 

[VoG]

CF should still work with a cell containing a formula.