Toni, thank you !!
All I do is make a ball with the color you want on the inside, then take a piece of gumpaste from the other color, roll it like a snake and make it long enough to roll around the ball. Flatten them together making sure they stick. Then roll as usual and cut. I use leftovers too as the two colors are mixed now and add one layer of that color too!!!
-- Dina @ miettes, http://www.facebook.com/pages/miettes/257790597632317