The best way to enhance the color of exterior natural stone, like flagstone, bluestone, travertine, and slate, is with a wet look sealer. The best wet look sealer to use on natural stone is the Armor WL550.
The Armor WL550 is a breathable, matte, wet look sealer that is designed to slightly enhance the natural coloring of the stone. It will not leave behind a film or coating, and is designed to work entirely below the surface. It behaves much like a water repellent sealer in that it reduces the absorption of surface water, and reduces damage and deterioration caused by water absorption.
Now, what if you want a gloss? In order to achieve a low to high gloss finish, an acrylic sealer needs to be used. The problem with acrylic sealers and natural stone is that they don’t work very well together. The failure rate with acrylic sealers on stone is very high. While some surfaces can get a couple of years out of an acrylic sealer, most acrylic sealers will delaminate within the first couple of months when applied to stone.
The best way to enhance the color of your stone, and protect it for up to 3-5 years against the damaging effects of water absorption, is to seal it the Armor WL550. If you like the look of your natural stone, and want to seal it without changing the look or color, the Armor SX5000 and Armor SX5000 WB are great options too.