It is easy to use a little science to decide the fastest color. Black gas tanks absorb more heat than they radiate. So on a sunny day the fuel is hot. Hot fuel is less efficient that cooler fuel so black cannot be the fastest on a sunny day. So logically that would imply silver, since it reflects the sun’s rays better, would be faster than black. But silver paint requires higher metal flake content than non-silver and therefore is heavier. Heavier is slower. The blue is close to black and for the same reasons that the black is slow, it also is slow. The black bike owners (and blue to some extent) of course are going to point out that by this logic they are the fastest on non-sunny days. Foolish people, of course they are the fastest on non-sunny days because they are the only ones on the road on non-sunny days! So what is needed is a color that is not overly dark and does not have an excess of metal flake in it. Why that is the burgundy of course. How clever of me to buy a burgundy bike. See, simple science and logic can solve any argument.
Just think how fast that burgundy bike would be without a flake in the saddle!