Count Cell Color with Count IF critiea VBA

Hey all i have a range of data i wish to count by cell color and if it contains a certain value (the month of April this year). This is my current Formula

=CountCcolorIF('2019-2020'!I3:AT3,'2019-2020'!I1,"15/04/2020")

currently only testing it with a single date rather than an entire month

And here is my VBA code

  Function CountCcolorIF(range_data As Range, criteria As Range, 
  cellvalue As Range) As Long
        Dim datax As Range
        Dim xcolor As Long
  xcolor = criteria.Interior.ColorIndex
  Application.Volatile
  For Each datax In range_data
  If datax.Interior.ColorIndex = xcolor And datax.Value = 
  cellvalue.Value Then
        CountCcolorIF = CountCcolorIF + 1
     End If
  Next datax
  End Function

As far as i can tell everything should be functioning how i intend it too but it’s not. Could anyone offer some insight as to why?