Cell Colour Change From Result In Adjacent Cell

I am trying to make the colour of cell change depending on the result in an adjacent cell and have found and adapted the following:

Private Sub Worksheet_Change(ByVal Target As Range)
Dim icolor As Integer
If Not Intersect(Target, Range("x4:x202")) Is Nothing Then
Select Case Target
Case 11
icolor = 43
Case 21
icolor = 43
Case 31
icolor = 27
Case 41
icolor = 27................