I always liked the red, white and black on the Chipmunks and Bulldogs that I flew as it looked smart and about as military as possible without getting out the olive green or AD grey. This grey and dayglo harks back to a much earlier scheme as illustrated by Tigger. Of all the schemes I think the recent black has been one of the best and is probably the best for conspicuity. If I was pimping my Chipmunk I'd probably go for gloss black and a highly polished aluminium cowling.