Sub nettoyage()
'Définis tes variables en tête de code
Dim mCell As Range
ActiveSheet.Unprotect "mdp"
For Each mCell In Selection
If mCell.Locked = False Then
With mCell.Interior
.ColorIndex = 3
'Pas obligatoire, option par dédaut
.Pattern = xlSolid
End With
End If
Next mCell
ActiveSheet.Protect "mdp", True, True, True
End Sub