Excel Conditional Formatting 3-color over one row applied to many rows

Since 3-color conditional formatting doesn't accept relative references (no matter how much you try to 'trick' Excel with INDIRECT, ADDRESS, etc.), your best bet is to use the method here (example was for 2-color formatting): https://superuser.com/questions/350378/excel-2007-conditional-formatting-so-that-each-row-shows-low-values-yellow-hig

This is the same as using the format painter on each individual row (using the format painter on multiple rows puts you back to square one where it looks at all the rows).

Sub NewCF()
    Range("B1:M1").Copy
    For Each r In Selection.Rows
    r.PasteSpecial (xlPasteFormats)
Next r
Application.CutCopyMode = False
End Sub

Also, there's no limit to the number of conditional formatting rules (at least in Excel 2010), but the more you have, the more potential there is for a negative impact on performance. You'll just have to try it and see. In the worst-case scenario, I would make 3-10 (or however many you can stand to make) individual rules based on a formula to create a "gradient", but this may be just as cpu-intensive.