我想将字母变成字

里面的字母d改成红色,供你参考.
Sub Changecolor()
Dim i As Integer
For Each Rng In Sheet1.UsedRange
i = InStr(1,Rng.Text,"d",vbTextCompare)
If i <> 0 Then
Rng.Characters(Start:=i,Length:=1).Font.Color = RGB(255,0,0)
End If
Next
End Su