California wants to ban black cars. Why? Because the AC has to work harder in a black car, since it absorbs sunlight.
Beyond the obvious “gee, that’s great, but what about the problems with car culture in general that are destroying the world?” question, there’s of course the question of liberty. But the thing is, even banning cars won’t solve the problem. You have to restructure society so that people have less need for cars, and so that people are more willing to, of their own volition, act in ways that are better for the world in general. You can’t say “don’t jaywalk,” you have to say “if you cross the street without making sure that the coast is clear, you’re endangering yourself and generally being obnoxious to the people who have to try to dodge you.” We’re not children. (Read: Fuck you, government)