I just had someone order red velvet with my raspberry Chocolate Buttercream. Not sure if it is going to taste right, hope it does!
on stuff like this, I tend to take the view of "why WOULDN'T it taste ok?"
Red Velvet is basically a chocolate cake with red food coloring (I acknowledge this is a super-simplified description .... it's meant to be). Chocolate cake with choc icing is pretty common.
I'm just one who doesn't understand who is in charge of making food rules, such as "red velvet MUST have cream cheese icing", and have never known anyone who has been arrested by the food police for violating one of these rules. 
Here's the most amazing white choc cream cheese icing recipe for red velvet that I discovered through a post on this website. I didn't care for the cake as much (I personally prefer Chef Stef's). But this icing is to die for! 
http://www.amazon.com/gp/feature.html?ie=UTF8&docId=1000407551
Just scroll down to the "Dreamy Creamy white chocolate cream cheese frosting". Oh, and I didn't specifically use the white choc (with cocoa butter ) they called for and it still turned out wonderful. Everyone I make this for wants the recipe!
Quote by @%username% on %date%
%body%