Mike,

That worked a treat. One further query, I want to paste data to the
range during a weekly setup. And do not want the event to trigger
until this has been done. How can I not have the event triggered in
this instance? The idea being that the original data is in grey text
and not bold and the amendments to the data are Black/Bold.

code now reads:-

Private Sub Worksheet_Change(ByVal Target As Range)

If Not Intersect(Target, Range("A1:A10", "C1:C10")) Is Nothing Then
With Target
.Font.ColorIndex = 1
.Font.Bold = True
End With
End If

End Sub

Thanks,
Matt