Option Explicit
Private Sub Worksheet_SelectionChange(ByVal Target As Range)
If Target.CountLarge <> 1 Then Exit Sub
Set Target = Intersect(Me.[C:R], Me.[3:4,6:7,9:10], Target)
If Target Is Nothing Then Exit Sub
Target.Interior.Color = IIf(Target.Interior.Color = &HFFA5&, &HF0F0F0, &HFFA5&)
End Sub