Car colors affects how fast the car heats up and how fast it cools down, White is the slowest, black is the fastest - actual max temperature is unaffected by color. Hence why Arizona, Nevada, Texas, New Mexico all have PLENTY of Black cars.
Where on earth did you get this information? Mythbusters tested this one using two otherwise identical rentals (year, make, model, no window tint, etc.) and the black car peaked, and held about 10F hotter than the white car. The reason you see dark colors in hot climates is that (a) some people want a dark color, and possibly never have to park in open sunlight and (b) modern vehicle AC systems are pretty effective at cooling the vehicle back down.
Speaking as the owner of a black car, black paint (and all dark vehicle colors) are subject to exactly the problems described in this thread. Also, they tend to fade and lose their clear coat faster, although with modern paints that should be a minimum of 8 years out unless it's parked in the sun all day, every day.