Claudine Helmuth is a multi-media collage artist, (check out her website: http://www.collageartist.com/) she teaches, and also has developed a wonderful line of studio paints with Ranger Ink, along with her marvelous Sticky Backed Canvas, a product I love to use to make images to adher to Nunn Design bezels, easy peezy! no gluing in required just cut or punch and take off the backing and stick right into the bezel.
Anyway, check out all of Claudine's tips and hints, and she has a really cool video on mixing colors! You can make 51 different colors out of her 15 paints by following the instructions on the video, and you can print out a pdf of the instructions too!
For the Color Mixing PDF visit: http://www.collageartist.com/chstudio_colormix.htm