Concrete can be colored in many ways; color hardener, integral liquid or powder, acid stains to name a few. The process of integrally coloring the concrete offers the advantage of the entire volume being colored; however, the surface strength is not increased as with the use of color hardener. Dry shake color hardener is another popular way to color concrete. You broadcast the hardener on the concrete as soon as it is floated for the first time. After letting the bleed water soak into the hardener you float and trowel it in. This method only covers the surface about 3/16 of an inch but it gives the concrete surface a longer wear life.