Well, for all that would be interested in painting, I would recomend "Krylon FUSION for plastics". I've done mine about 2 weeks ago and no scratches yet. You can merely try scartching the paint off with your fingernails and nothing will come off; feels like it's the plastic itself that has the color.
I used a total of 4 cans of "Satin Black" Krylon Fusion and about 2 1/2 cans of Duplicolor Clear Coat. About $45.00 to include a can of Paint Thinner to prep/wipe the material.
There are Dye spray cans out there that you can buy also, I never worked with Dye though, so i can't tell you anything about it...