Exceeding 3 Criteria Limit In Conditional Formatting

The code segment from "Get Around Excels 3 Criteria Limit in Conditional Formatting" works perfectly if I type the variable directly into the cell, but not in a range of cells. That is to say, if I copy the source cell to a range of cells I receive a "Run-time error 13: Type mismatch" error". Is there a way to get around this? This is the code segment I've tried in the worksheet.

Private Sub Worksheet_Change(ByVal Target As Range)
Dim icolor As Integer
If Not Intersect(Target, Range("b2:q53")) Is Nothing Then
Select Case Target
Case "IBBCH", "ibbch"
icolor = 36 'light yellow
Case "OBBCH", "obbch"
icolor = 34 'light turqoise
Case "OBBRDG", "obbrdg"
icolor = 35 'light green
Case "LNCH", "lnch".........................