Private Sub Worksheet_BeforeDoubleClick(ByVal Target As Range, Cancel As Boolean)
If Not Intersect(Target, Range("A:A,C:C")) Is Nothing Then 'Range("A:K")
Select Case Target.Interior.ColorIndex
Case 2, xlNone: Target.Interior.ColorIndex = 5
Case Is = 5: Target.Interior.ColorIndex = 4
Case Is = 4: Target.Interior.ColorIndex = 3
Case Is = 3: Target.Interior.ColorIndex = xlNone
End Select
Cancel = True
End If
End Sub