i used regular latex paint. i'll tell you what though, make sure you get off all the excess silicone, and scrape with a razer wherever they dropped a little. it won't be paintable, and it looks really stupid.
Use a Good quality Outdoor latex paint (gloss). and roller. It will look smooth from the inside and krinkeld on the outside. also put it on think....like 4 coats. this will help with scratches and salt creep down the road.....also I Strongly reccomend BLACK. this will make LR and coraline stand out way more then blue.