I just switched to Valspar Armor from using Rustoleum. At Lowe’s, they can mix any color you want. Sells by the gallon. The base is clear and I buy it separate to use as as a protective coat on top of the color. Before I spray it, I mix in a capful of Japan Dryer into the paint(quart). It acts as a catalyst and makes the paint dry hard and shiny.
edit: not sure how long it will last in the weather, just started using it this year.