I simply used Benjamin Moore Arborcoat Solid Stain to paint these, with the exception of the brick red color. It was Semi-Solid Stain. I just had my son wash them and when they dried, I began painting on the stain. It wasn't a hard job, just super time-consuming. It took many hours. But I'm very happy with the results. I've been working on this over the last few days and when I scraped over what was painted on a couple of days ago, it didn't come off at all so I feel it will be durable. It makes one wonder what else I can do with exterior solid stain that was designed for wood.
And now . . . the mats before their makeover!