Option Explicit
Private Sub Workbook_SheetBeforeRightClick(ByVal Sh As Object, ByVal Target As Range, Cancel As Boolean)
Cancel = True
With Target
If .CountLarge = 1 And IsEmpty(.Value) Then .Interior.Color = RGB(255, 0, 0)
End With
End Sub
Private Sub Workbook_SheetBeforeDoubleClick(ByVal Sh As Object, ByVal Target As Range, Cancel As Boolean)
Cancel = True
With Target
If .CountLarge = 1 And Not IsEmpty(.Value) Then .Interior.Color = RGB(0, 0, 255)
End With
End Sub