This is in response to the original question, it is a simple modification of Vincent's response:
If it is a named range (using the UI: Insert, Name, Define):
Dim c As Range
For Each c In Range("ColRange").Cells
If c.Value >= 0 And c.Value <= 500 Then
c.Interior.Color = RGB(255, 0, 0)
ElseIf c.Value >= -5 Then
c.Interior.Color = RGB(255, 255, 200)
Else
c.Interior.Color = RGB(0, 255, 0)
End If
Next c
If it is a range object, defined in the code:
Dim c as Range
For Each c In colRange.Cells
If c.Value >= 0 And c.Value <= 500 Then
c.Interior.Color = RGB(255, 0, 0)
ElseIf c.Value >= -5 Then
c.Interior.Color = RGB(255, 255, 200)
Else
c.Interior.Color = RGB(0, 255, 0)
End If
Next c
I think Vincent's response won't quite work because, it attempts to operate on the entire ColRange range, inside the If Then, rather than operating on each cell one at a time. (For this reason, you may also want to wrap it with Application.ScreenUpdating = False