A recent trend is not to use spray paint, but vinyl dye, available at most auto parts stores.

It goes on just like spray paint, needs almost no prepping, will not chip, and will not cost an arm and a leg. After seeing the finished effect, it's hard to believe it's not the original color of the plastic.

As for disadvantages, it won't work on metal, and it has very strong fumes. Make sure you do this outside.