Sub Test()
Dim i%, j%, Dl%, Dc%
Dim Ws As Worksheet
Set Ws = Sheets("05,07,21")
Dl = Ws.Range("A" & Rows.Count).End(xlUp).Row
Dc = Ws.Cells(4, Columns.Count).End(xlToLeft).Column
For i = 7 To Dl
For j = 3 To Dc
If Ws.Cells(i, j) <> "" Then
Ws.Cells(i, j).Interior.Color = xlNone
With Ws.Cells(i, j)
.Value = "ON"
.Font.Name = "Arial" '> Pour uniformiser la police de caractères
.Font.Color = RGB(0, 0, 0) '> Pour une couleur de police uniforme
End With
End If
Next j
Next i
End Sub