Have a look at <a href="http://www.wikihow.com/Apply-Conditional-Formatting-in-Excel">conditional formatting</a>. You may not even need VBA to do this.

That being said, the VBA code would look something like this:

<pre><code>Public Sub colorit()
 Dim colRange As Range
 Dim rowNum As Integer
 Dim rnum As Integer
 
 rnum = 20
 Set colRange = Range(Cells(2, 9), Cells(rnum, 9))
 
 For rowNum = 1 To colRange.Rows.Count
 If colRange.Cells(rowNum, 1).Value &lt;= -5 Then
 colRange.Cells(rowNum, 1).Interior.Color = RGB(0, 255, 0)
 ElseIf colRange.Cells(rowNum, 1).Value &lt;= 0 Then
 colRange.Cells(rowNum, 1).Interior.Color = RGB(255, 255, 0)
 ElseIf colRange.Cells(rowNum, 1).Value &lt;= 500 Then
 colRange.Cells(rowNum, 1).Interior.Color = RGB(255, 0, 0)
 End If
 Next rowNum
End Sub</code></pre>