Private Sub Worksheet_SelectionChange(ByVal Target As Range)
Dim C As Range, N1 As Byte, N2 As Byte
If Target.Count = 1 Then Exit Sub
For Each C In Target
If C.Interior.Color = [I1].Interior.Color Then N1 = N1 + 1
If C.Interior.Color = [I2].Interior.Color Then N2 = N2 + 1
Next
MsgBox "Dans " & Target.Address & " il y a " & Chr(10) & _
N1 & " cellule" & IIf(N1 > 1, "s", "") & " en jaune et " & _
N2 & " cellule" & IIf(N2 > 1, "s", "") & " en rouge !"
End Sub