Private Sub Worksheet_BeforeDoubleClick(ByVal Target As Range, Cancel As Boolean)
Cancel = False
If Not Intersect(Range("a3:a100"), Target) Is Nothing Then
With Target
StrColor = .Interior.ColorIndex
.Interior.ColorIndex = IIf(StrColor = -4142, 3, IIf(StrColor = 3, 4, -4142))
End With
End If
Cancel = True
End Sub