Sub test()
For n = 1 To Sheets("Feuil2").Range("A" & Rows.Count).End(xlUp).Row
If Sheets("Feuil2").Range("A" & n) <> "" Then
For m = 1 To 34
If Sheets("Feuil2").Cells(n, m) <> Sheets("Feuil3").Cells(n, m) Then
Sheets("Feuil2").Cells(n, m).Interior.ColorIndex = 4
Sheets("Feuil3").Cells(n, m).Interior.ColorIndex = 4
End If
Next
End If
Next
End Sub