Everybody knows (even The Orks): red cars are faster.
I painted red (almost) all my online racing cars and i have a new, very special one. One that i'll using frequently the next month and i want it in the "best looking red".
The Pearl Red from the LF-A, Competition Red from the 8C Alfa and Red Metalic from the Evo X are wonderful, much better IMO than the reds Ferrari has on offer (too flat and not deep enough or too dark and not red enough).
I spent a fair bit of time sorting through them. By far the best I found is K2red, but it's rare (got it on one of the Mazda prize cars, haven't seen it anywhere else).