For an optional parameter, you can specify a default value.
In the following example, default intensities are set for the red, green, and blue components of the color of the selected cell range.
Specifying a default value for an optional parameter
Sub Color(Optional Red As Integer = 0, Optional Green As Integer = 255, _ Optional Blue As Integer = 0) Selection.Interior.Color = RGB(Red, Green, Blue) End Sub Sub DemoDefaultValues() Color Blue:=175 End Sub