AmeriColor Super Red & Super Black gel paste food colorings.
Yep, that's it.
No adding cherry juice to red icing. No mixing of every color in your arsenal to make black. No stirring 2 containers of red food coloring into icing and still winding up with pink. (When I first started decorating cookies, I tried it all.)
Oh, did I mention these have no yucky aftertaste like some other colors?
You can find it many places online: Bake It Pretty, Layer Cake Shop, Sweet Baking Supply, Copper Gifts and, of course, Amazon. If you have a bakery supply store in your town, I bet they'll have it, too. I almost forgot...Hobby Lobby!!!
Making red & black icing the easy way...works for me!