Never tried ther paint-plus-primer stuff, but painted a lot of aluminum. Paint on aluminum as it sits has a life measured in minutes, almost. Aluminum forms a skin of oxide that offers little "tooth" for bonding. (Oxides are often created by some types of cutting fluids, and the oxide acts as a super-slippery lubricant in machine work.) That oxide needs to be removed, usually by acid-etching, and to futher protect the metal it is then treated with alodine to form an impermeable barrier to oxygen. The acid leaves microscopic pits in the metal for the primer to mechanically bond to. The paint bonds to the primer. Zinc chromate is the usual primer for aluminum, as the zinc will act as a sacrifical element to preserve the aluminum.
Yellow? Excellent choice. All other colors are wannabes. But today's yellows are nearly transparent because they no longer use lead in the pigments. Paint the surface white first, and the yellow will be brighter and you'll use less of it.
