A red Porsche will obviously get more attention than a gray Nova. I used to make high speed runs between Buffalo and NYC back in college, driving a battleship grey '77 Chevy Nova. It was totally nondescript, a wonderful V8 speed machine. If you can, try to get a dark car. Black, Navy Blue, Hunting Green are all nice.
Cops see brighter colors better, as do most humans.
Bright red, white, blue, or green are not wise for speed. Think BMW 540i, Nissan Maxima, Taurus SHO, Volvo 850 turbowagon. It's been rumored that laser detectors have a hard time working on dark and dirty cars. Get in the right lane. The cop might not be after you, but take it easy for a bit, just in case.