So do I. And I also like the idea of randomizing the extra color for the top player (and hence, for all players). But I don’t like the idea of players tossing for color in the last round.
My method solves all three problems. Randomize once for the top quad. Heads, list players 1-2-3-4. Tails, 4-3-2-1. For the second and subsequent sections, reverse the sequence (if 1-2-3-4 in the top quad, then 4-3-2-1 in the second, etc).
With final-round pairings of 1-2 and 3-4, the top two seeds face each other, regardless. The top seed gets white or black, 50-50. And no messy final-round tossing.
You could collect a forfeit deposit ($5 or $10) from each player when you take their entry fees. Return it when they complete all three games (or, for that matter, as soon as they begin their third game). If any player drops out, give that player’s forfeit deposit to the opponent who was deprived of a game (along with the opponent’s own forfeit deposit, of course).
Bill Smythe