Painting plastic?
P.S. You didn't say whether you are painting glow power, gas or electric. If it's gas or electric you can find a bewildering array of colors in most hardware stores. If you are painting a glow plane you will certainly need a fuelproof paint which pretty much limits you to the colors available from hobby suppliers. You can use other paints if you give them a few coats of clear fuelproofer that's available from most all hobby suppliers.