Sub ColoriageDoublons()
Dim D1, D2, P As Range, C As Range, a(), n As Long, L As String
[A:A].Interior.ColorIndex = xlNone
Set D1 = CreateObject("Scripting.Dictionary")
Set P = Range("A2", [A65000].End(xlUp))
For Each C In P
If C.Value <> 0 Then D1.Item(C.Value) = D1.Item(C.Value) + 1
Next
Set D2 = CreateObject("Scripting.Dictionary")
For Each C In P
If D1.Item(C.Value) > 1 Then
C.Interior.ColorIndex = 3
If D2(C.Value) = "" Then D2(C.Value) = C
End If
Next
a = D2.keys
For n = 0 To UBound(a): L = L & a(n) & vbLf: Next
MsgBox "Les valeurs suivantes sont en doublon :" & vbLf & L, 64, "Attention..."
End Sub