I have a request for yellow cake w/ choc frosting. the frosting must be white. Is there a flavoring I can use to achieve this?

Chocolate flavored *white* icing?
Well, there are 2 choices. Make your regular icing and add white chocolate flavoring (Lorrain Oils sells it - usually in the candy dept especially at Hobby Lobby.)
Use white chocolate pudding as icing or add it to b'cream.

kakeladi....thanks for your help. Do you just add a package of pudding to the b/c recipe? I use indydebi's b/c

You could also add melted white chocolate chips to your buttercream. Nestle's taste good and so do Ghiradelli's. They don't have that waxy flavor that some others do.

ok, so whatever I decide to use, I just add to the b/c recipe??

yes just add to your buttercream
i got chocolate flavoring(and its white in color) from spice barn .com

goodluck