We had a tandem that on the occasion of its first scratch turned out to be a perfect match with some nail polish from my wife's makeup kit that she used to call Come-F***-me Red. Agree it works way better and is more durable than you really think it has any right to be, considering.

A big loveable guy we know took the front end of his tandem frame (it has S&S couplers) to the cosmetics counter at the Hudson's Bay Company store. The young women behind the counter were thrilled to work on matching up a colour for him -- and they nailed it. Metallic green, no less....