In Excel, how do I conditionally change a row's fill color?

This is what I’d like to do:
Say I have a Column B which contains certain codes. In some rows, the code might be ‘MDVA’, in others, ‘L’, ‘R’, or ‘Cx’. For any row in which the value is ‘L’, for example, I want to make the background color light blue for the entire row, not just that one cell containing ‘L’. For any row in which the value is ‘MDVA’, I want to make the background color light yellow.
How do I do this? Is there a way to do this without getting into VB? Functions and formulas are OK.