I've now made three colours from some almost-forgotten fleeces and my new wool combs. The fleeces are an unidentified family pet sheep (white) and a zwartbles (black). I've used the combs to blend the two for the grey which I'm delighted with.
Just a short while in Ravelry's pattern search turned this up. (Check Slouch from Interweave) It only gives one size and calls for slightly thicker yarn than I've made but it should be an easy pattern to adjust. It'll also bring in new skills for me, it'll be the first 'double knitting' that I've done. One colour per round, lots of slipping. Gagging to get started on this one.