I'm making a birthday cake. They want Red Velvet with my coconut filling(it basically tastes like the inside of a Mounds) Should I just do a regular buttercream frosting? They don't want cream cheese.  I just want to hear what others have done or would do instead of cream cheese frosting. Thanks!

this has similar tang to it -- similar to cream cheese without refrigeration issues -- even though the idea of vinegar in icing is a little scary -- it's really good -- http://www.cakecentral.com/recipe/61811/white-balsamic-american-buttercream -- make it as mild or as bold as you like

another american buttercream icing -- you could substitute buttermilk for the liquid in an american icing which is another mild icing would go good

but i don't think you can beat the classic wilton french buttercream aka ermine icing -- it's the original red velvet icing

http://www.wilton.com/french-buttercream-icing/WLRECIP-181.html

there are other recipes -- that's the one i've used since the 80's

i don't remember mine ever being that yellow

I've had red velvet cake with a marshmallow buttercream and it was good!