Sub coloriage()
Application.ScreenUpdating = False
Couleur = 36
For i = 2 To [A65000].End(xlUp).Row
If Cells(i, 1) <> Cells(i - 1, 1) Then Couleur = IIf(Couleur = 38, 34, 38)
Cells(i, 1).Resize(, 2).Interior.ColorIndex = Couleur
Next i
Application.ScreenUpdating = True
End Sub