Bonjour,
Une proposition.
Evite les cellules fusionnées !...
Cdlt.
Private Sub Worksheet_Change(ByVal Target As Range)
Dim color As Long
If Target.Address = "$B$5" Then
color = Target.DisplayFormat.Interior.color
With Target
.Offset(2).Interior.color = color
.Offset(4).Interior.color = color
End With
End If
End Sub