This is a great tutorial for beginners to learn how to add 
color to fondant or gumpaste. Don't be scared to add color. But don't add it all at once or it will be more difficult to mix.
 I will add that my favorite red is the True Red from 
Chefmaster. I have tried Americolor and it works well but the pigment from Chefmaster is stronger. 

The black from Chefmaster and Americolor are pretty good too. For bright colors, these 2 companies are my favorites. Wilton have other colors I love but some of their brighter colors are not as strong. I do love other colors they offer.