What is the best way to get jet black royal icing, jet black gumpaste, and jet black buttercream?

I buy black gum paste, and america color is great. But keep in mind that black royal icing and buttercream will stain peoples teeth

Whenever I have to use jet black in any medium I start with a brown base color or you can use dark chocolate base, then add a little color at a time until it reaches the color you want. Just remember the color will darken after time, so if you can make your black a couple of days ahead.