Red gets the most speeding tickets. XD So I wouldn't go for that one. Yellow is kinda in the middle because some of the hues are ugly and some look really nice.
My favorite colors on cars are bright green, black, gray, silver, charcoal and the opalescent where the truck will look black, bluish-purple or greenish black depending on how the sunlight hits it.
I HATE colors like pink, weird teal colors like the Malibu comes in, white (too hard to keep clean) etc.
Purple is iffy another one that just depends on what kind of purple it is.