[ESS] noweb fontification

[Bill Rising]

Hey folks,

Is there a simple way to have different fontification for basic text  
in the different chunks when using noweb-mode?

Here's the idea:

In the doc (for me: LaTeX) sections of the .Rnw document, use the  
normal fontification.
In the code sections, change the default nothing-special font to  
either have a different foreground color or have a different  
background color?

It would seem that I could customize something in ESS to do this, but  
I don't see it. It sure would make editing long noweb docs easier, at  
least for a newbie.

Thanks for any tips,

Bill