I attempted to make black b/c using Wilton gel color. I am so glad I tasted it before I used it. It tasted HORRIBLE. How do I make black b/c without the awful taste.
You can start with chocolate buttercream.
If you have an airbrush try that. I recently airbrushed a whole cake black and it did not taste any different.
I buy my black icing and fondant. I can never get it just right.
I start with chocolate buttercream. Then you don't have to add so much coloring, but airbrushing works good too.
You can frost the cake in white buttercream. Refrigerate it, then skim coat the cake with the dark color. This works with European buttercreams.
Wilton black gel coloring is nasty, probably because you have to use so much of it to get the color you want. I agree with the others in using chocolate buttercream as the base - it'll get black faster with less coloring. I personally have started using the Americolor black food coloring gel. It only takes a little bit to get my white buttercream black, as opposed to using gobs of the Wilton gel. Since you're not using so much of the gel, the buttercream doesn't end up tasting like chemicals.