COUNTIF Of Conditional Formatted Coloured Cells With VBA

I know the VBA code to count cells from a data set that were manually colour-coded.

The problem is that the code (pasted below) doesn't seem to pick up cells that were coloured via Conditional Formatting. How do I do this? What is the VBA (if there is one)?

Function COLORCOUNT(varRange As Range, varColor As Range)
Dim cell As Range
For Each cell In varRange
If cell.Interior.ColorIndex = varColor.Interior.ColorIndex Then
COLORCOUNT = COLORCOUNT + 1
End If
Next
End Function