Hello!  I'm going to be baking some cupcakes for Saturday and the mom wants the frosting to be divided into all the colors of the rainbow - at that intensity, too.  A couple of questions as I plan this out:

1. Half of the cupcakes will be iced with BC, the other half will have cream cheese frosting.  I've never tried to color cream cheese, will it work just the same as BC?

2. I know I can get the right shades by using paste/gel food coloring, but, oh, that royal blue and red aftertaste... ugh.... SO....if I made colored sugars,  would I be able to frost in advance and roll the tops in the sugars?  Would the sugar melt into the frosting?  Or is this something I would have to do the day-of and then deliver?

Thanks for your input and thoughts... 

Not sure about colored sugars but I'm a big fan of the wilton icing colors, they are potent and don't add liquid to your icing. They even have "no taste" red.

I've colored small batches of CC frosting for those traditional carrots on carrot cakes and it color just fine. Again, I don't use liquid colors because the high fat content in CC frosting and I don't have issues with separation.