I've got a couple of calabashes as well, but I don't smoke them very much since Balkan Sobranie and Bengal Slices disappeared from the market. These are the only two tobaccos that I really love in a Calabash. Every now and then I'll crack open one of my few remaining tins of Bengal Slices and fire up a Calabash.
As for coloring, a coloring bowl like the one shown with the Cavalier is really the secret. I've got three coloring bowls, a smooth meer, a pebbled meer (shown w/ Cavalier), and an XL briar coloring bowl made for me by Mike Butera after much hounding.
AFAIK it's the only one in existence, and I use it for smoking my english tobaccos in my meerschaums.