For formation flying I think it's best to have single smoke from the fuselage so the wingy isn't flying in the lead's smoke.
Wingtip smoke is nice to show maneuvers and for solo aerobatics. Triple smoke might be a bit much. I'd rather see longer lasting smoke than triple smoke if there was a tradeoff.
I think red, white, blue, and green would be good choices for colors. I don't know if there are any issues to limit the pallet.
--)-FLS----
Musketeers