UDF to count colored cells always gives zero

I want to count the number of colored cells in a column but I keep getting zero even when there are colored cell present

Thanks

Sub iCountColors()
Dim ws As Worksheet
Dim Rng As Range
Dim LR As Long

    Set ws = ThisWorkbook.Sheets("Nodes")
    With ws
            LR = .Range("A" & .Rows.Count).End(xlUp).Row
       Set Rng = .Range(.Cells(2, 2), .Cells(LR, 2))
    End With
        
    MsgBox "There are:  " & CountColors(Rng) /2 & "  Dupes in Column B"

End Sub

Function CountColors(RangeToCount As Range) As Long
Dim ColorCell As Range
Dim myCount As Long

    Application.Volatile

    For Each ColorCell In RangeToCount
      'If the cell has any color, add it to the running count.
      If ColorCell.Interior.ColorIndex = RGB(255, 0, 255) Then myCount = myCount + 1
    Next ColorCell
    
    CountColors = myCount
 
End Function