While I don't have and haven't read any studies, my initial thoughts are in line with basher. A brightly colored car stands out more against the background. This would make the car more noticeable and seemingly make speed enforcement a bit easier. However the actions of the driver are the primary reason a car is pulled over, not the color of it. If you're a good driver in a white car you are going to be a good driver in a red car.
But when a long train of abuses and usurpations, pursuing invariably the same object, evinces a design to reduce them under absolute Despotism, it is their right, it is their duty, to throw off such Government, and to provide new guards for their future security.
Translation for the intellectually challenged: If the government screws the people too much, it is the right and duty of the people to revolt and form a new government.