Sub DoublonsDeuxColonnes()
couleurs = Array(1, 3, 4, 6, 7, 8, 14, 15, 17, 20, 22, 24, 26, 27, 28, 33, 34, 35, 36, 37, 38, 39, 40, 42, 43, 44, 45, 46, 50, 53)
Set mondico = CreateObject("Scripting.Dictionary")
For Each c In Range("A1", [A65000].End(xlUp))
clé = c.Value & c.Offset(, 3)
mondico.Item(clé) = mondico.Item(clé) + 1
Next c
For Each c In Range("A1", [A65000].End(xlUp))
clé = c.Value & c.Offset(, 3)
nocoul = (Application.Match(clé, mondico.keys, 0)) Mod UBound(couleurs)
If mondico.Item(clé) > 1 Then MsgBox "Doublon pour " & clé & " ligne" & c.Row: c.Resize(, 4).Interior.ColorIndex = couleurs(nocoul)
Next c
End Sub