Remplir couleur cellules

Private Sub Worksheet_BeforeDoubleClick(ByVal Target As Range, Cancel As Boolean)
Dim X As String, Y As Integer
On Error Resume Next
    If Target.Column > 0 And Target.Row > 8 Then
'il faudra limiter la zone de fonctionnement de la macro en ajoutant
'Target.column < nb de noms et Target.Row < à nb de jours
    X = Range("A1")
    Y = Target.Count > 1
    Cancel = True
    If ActiveCell <> "" And ActiveCell = X Then
        Target.Clear
    Else
        Target = X
    End If
    Select Case ActiveCell
        Case "M"
            Target.Interior.ColorIndex = 44
        Case "S"
            Target.Interior.ColorIndex = 42
        Case "N"
            Target.Interior.ColorIndex = 38
    End Select
    End If
End Sub