What generous of paint should I use to paint plastic (must be weather/water-proof)? See, I'm painting black on my white house numbers because it just...

See, I'm painting black on my white house numbers because it just stand out near the background.

Where can I get the paint? How much does it cost?

Thanks within advance,
Stephen
Answers:    Wal-Mart has a spray paint made of late for plastic. It's made by Krylon and it has a picture of a plastic lawn bench on the front of the can. It is probably around $2-$3.
Try Krylon Fusion, it's specially designed to be used on plastic.