This is my first request, so sorry if something is incorrect.

I’m working on Excel 2019 and created a custom function:

' Color & Sum
Function ContColor(InputRange As Range) As Double

    Application.Volatile
    
    Dim cell As Range
    Dim sum As Double
    Dim colorPD As Long

    sum = 0
    
    colorPD = RGB(153, 255, 102) ' My Color
    
    For Each cell In InputRange
            If cell.Interior.Color = colorPD Then
                sum = sum + cell.Value
            End If
   
    Next cell
    
    ContColor = CLng(sum)

End Function

Now, I would like to change the optional colorPD to a default color like this:

Function ContColor(InputRange As Range, Optional colorPd As Long = RGB(153, 255, 102)) As Double

transforming the function like this:

Function ContColor(InputRange As Range, Optional colorPd As Long = RGB(153, 255, 102)) As Double
    Application.Volatile
    
    Dim cell As Range
    Dim sum As Double

    sum = 0
    
    For Each cell In InputRange
            If cell.Interior.Color = colorPD Then
                sum = sum + cell.Value
            End If
   
    Next cell
    
    ContColor = CLng(sum)

End Function

But I get error. Someone help me?