There are many different topside boat paints and qualities, generally the more you spend the better the results.
Duralux High Gloss Marine Enamel is affordable and easy to apply and only recommended for above the waterline or moderate use on the bottom (a day or so in the water, not extended periods). This topside paint works best in very thin coats; see the prep recommendations found on product page on “how to use” tab. Duralux marine enamels does have a limited color offering in a flat finish, but those color choices are limited to their camouflage paint colors.
You also have a choice from Supermarine Paints that can be used above or below the waterline and come in a few different styles. The Revolution (great option if rolling/brushing) or Mono Epoxy (durable and looks best sprayed) are the easiest to use and usually customers choose the SuperMarine Etching Primer (SM 664D) for the primer. They are also available in your choice of sheen (satin or gloss). Click on “view more” for the paint and use the specification/how to use tabs for detailed instructions, coverage and preparation on any of the product pages. The “work horse” is the Two Part Epoxy, most durable of the Supermarine choices with the top of the line selection is Ironside. The previous two paints are available in flat and semi gloss as well as satin and gloss.
The best available boat paint for the topside with the best finish is Awlgrip, most expensive but best results and loved by customers. Awlgrip marine paint also requires a little more “do it yourself savy” to apply these paints, and require the correct activators and reducers when applying. The manufacturer of Awlgrip recommends it for above waterline use only.
So your topside boat paint choice depends on your budget and the amount of time you want to spend on your boat paint application.