Sub Couleur()
Application.ScreenUpdating = False
With Range("A1:T" & Cells(Rows.Count, 1).End(xlUp).Row)
.Columns(1).Insert xlToRight
.Columns(0) = "=1/MOD(ROW(),2)"
Intersect(.Columns(0).SpecialCells(xlCellTypeFormulas, 16).EntireRow, .Cells).Interior.ColorIndex = 15
.Columns(0).Delete xlToLeft
End With
End Sub