Dry concrete scatters a lot of white light, so most of the light shining on it is scattered. The result: the concrete looks pale and lifeless. Wet concrete, polished concrete and concrete sealed with certain sealers reflects more of the light as colored light (the color of the concrete) and has less white light scattering. That’s why the concrete looks richer and more colorful.
“Wet-look” sealers are sealers that make the concrete look like it’s wet with water. They pop the color and are typically very glossy. Not all finishes that pop the color make the concrete glossy. But high gloss finishes give the “wettest” look because of the combination of gloss and low white light scatter.
If you think clear sealers won’t affect the color of concrete, you’re right in some instances and wrong in others. There are a few different types of film-forming sealers, all of which are available in water- and solvent-based versions; acrylics, urethanes, polyaspartics and epoxies. These protective coatings can produce a variety of sheens, varying in intensity, to highlight the beauty of a decorated surface and enhance its color.
Solvent-based acrylic sealers enrich hues beautifully. A solvent-based acrylic sealer also will bring out warmer colors, such as yellow and orange, and increase color contrast. If an area contains mottling between darker and lighter versions of the same color, that will be emphasized by a sealer. If you want to test out how a wet look sealer will look you can run a wet mop over the slab and to see what it will look like.
All sealers will affect the depth of color somewhat, although some water-based acrylic sealers do little to deepen the color. In effect they are the opposite of wet look sealers. Though the surface might be shiny from the acrylic, the color of the concrete still looks pale as if it were dry and unsealed. Film-forming products such, as a water-based acrylic, with a low-gloss or satin finish are a great option if a more natural look is desired, as they usually don’t require as much maintenance. Solvent-based acrylics will typically enhance colors more than their water-based counterparts.