Answer: a protective film or a penetrating treatment.
A treatment will protect your pavement from water, stains and external aggressions (wind, pollution, etc.). It is not always necessary, on resin for example, but is useful for paving stones in natural stone, reconstituted stone and concrete. You can use a stone varnish which will deposit a protective film on your pavers. Not only will they look smoother, but they will also be protected against water and grease. Cleaning will also be facilitated. Conversely, two other treatments will penetrate the pavers: the water-repellent treatment against water, to be applied in several layers; oil-repellent treatment against greasy products such as traces of wheels or soles. These last two do not change the color of the pavers since they do not leave a film on their upper part.