Well...ok. No need for primer, but you will need to LIGHTLY sand them first to give the paint a surface to adhere to. Use 600 grit and a water hose, oh and make sure the sandpaper is for wet sanding. Be sure to wipe the surface free of dust and contaminates with alcohol. Remember...lightly.
One more thing if I were you I would do this in a garage with the door shut...that color really oversprays and any little amount of wind will carry it everywhere. Cut up paper sacks and use them to mask off your area.
rainshdw