If you want to know the color of a cell that has been colored by a conditional formatting rule (CFR) then use Range.DisplayFormat.Interior.Color
¹.
If you want to definitively know what color a cell may or may not have been colored by a CFR you need to iterate through the CFRs that could be affecting that cell and look at each of the Range.FormatConditions(*x*).Interior.Color
.
Documentation: range.DisplayFormat
¹ Note: .DisplayFormat
is not available for a worksheet UDF.