Yesterday I played around with mixing my own custom colors. Basically, you take two rods of glass, heat the ends, smoosh them around and pull them into something resembling a new rod. Actually, it's more like a thick stringer when I do it. :) I then made clear beads and encased them with the new color - the clear base makes it so my skinny rod of glass will go farther.
This set is made from effetre rosewood and dark ivory mixed about 50/50. So far it's one of my favorite custom colors! This is something I will most likely continue to play with, as a matter of fact, I'm off to play now! Have a great day :)