My favorite size/color for chironomid fising is a size 6 either brown or green and is tied to look just like a wooly bugger.

Actually I do carry some chironomide, mostly red and pink, but they are my last resort, even in a heavy hatch. I just don't like fish a fly so slow that if you actually move it, you're fishing too fast. I'm happy to report that it is very seldom that I have to resort to midges.