Conditional Format Multiple Criteria VBA

I have 2 columns of data - Name (A) and Index (B) - and the following VBA, so when Index (B) is a certain value (or within a specific range) that Index (B) cell changes color:

Private Sub Worksheet_Change(ByVal Target As Range)

    Set I = Intersect(Target, Range("B2:B10"))

    If Not I Is Nothing Then
        Select Case Target
            Case 0 To 50: Newcolor = 37     'light blue
            Case 51 To 100: Newcolor = 46   'orange
            Case 101 To 150: Newcolor = 12  'dark yellow
            Case 151 To 200: Newcolor = 10  'green
            Case 200 To 250: Newcolor = 3   'red
            Case "A": Newcolor = 13  'violet
            Case "B": Newcolor = 54  'plum
            Case "C": Newcolor = 38  'rose
        End Select
        Target.Interior.ColorIndex = Newcolor
    End If

End Sub

This works well for multiple Conditional Format, but only changes the cell color for Index (B).

How can I modify this so the value in Index (B) will also change the cell color for Name (A) adjacent?

e.g. "215" in B5 changes cell B5 and A5 to red. (using Excel 2003)