Private Sub macro1()
Dim c As Range
For Each c In Range("c3:f38")
Select Case c.Value
Case Is <= 1
c.Interior.ColorIndex = 4 ' vert foncé
Case Is <= 2
c.Interior.ColorIndex = 10 ' vert foncé
Case Is <= 3
c.Interior.ColorIndex = 6 ' jaune
Case Is <= 4
c.Interior.ColorIndex = 46 ' orange
Case Is <= 5
c.Interior.ColorIndex = 3 ' rouge
Case Else
c.Interior.ColorIndex = xlNone ' blanc
End Select
Next c
End Sub