[MiguelHudnandez]

Not necessarily. If you say "I will only buy a car that's green," and money is no object, you are likely to spend less money than if you buy a car of any other color. However, if you want a 2009 Honda Civic, a green one may not necessarily be cheaper than a blue or black one.

My theory is that there aren't many green luxury cars out there (think black!), but plenty of cheap commuter cars that are green. Another theory: younger people want green and younger people happen to spend a lot less on cars on average.

I went looking through the categories and the only time green is not the cheapest is when it's a station wagon. In that case, red is cheaper than green, but not by much.