Sub DoubleCoul()
For i = 2 To Sheets("Feuil1").[C65536].End(xlUp).Row
For j = 1 To Sheets("Feuil2").[A65536].End(xlUp).Row
If Sheets("Feuil2").Cells(j, 1) = Sheets("Feuil1").Cells(i, 3) Then
Sheets("Feuil1").Cells(i, 2).Interior.ColorIndex = 6
End if
Next
Next
End Sub