Private Sub Worksheet_BeforeDoubleClick(ByVal Target As Excel.Range, Cancel As Boolean)
If Application.Intersect(Target, Range('A1')) Is Nothing Then Exit Sub
With Target
If .Interior.ColorIndex = 48 Then 's'il y a la couleur....
.Interior.ColorIndex = xlNone
.Value = ''
Else 'sinon on ajoute couleur et valeur....
.Interior.ColorIndex = 48
.Value = Range('B1')
End If
End With
End Sub