Option Explicit
Sub Colorisation()
Dim DerL&, Lig&
DerL = Feuil1.Range("A" & Rows.Count).End(xlUp).Row
For Lig = 2 To DerL
Cells(Lig, 1).Interior.ColorIndex = 0
If Cells(Lig, 1) >= Cells(2, 3) And Cells(Lig, 1) <= Cells(3, 3) Then Cells(Lig, 1).Interior.ColorIndex = 40
Next
End Sub