The demand for colored concrete is increasing. Paint provides one means of producing colored concrete and for walls and ceilings it is satisfactory. On flatwork, however, it deteriorates with abrasion. The use of colored aggregates is another way of producing colored concrete and this type of finish is much more permanent than paint. In addition to the color of the aggregate two other factors influence the color in exposed aggregate concrete: (1) the amount of the surface filled by the aggregate and (2) the color of the cement paste matrix. Pigments added to the mix or dusted on the surface of wet concrete slab are the most popular method of coloring concrete. If the pigment is to be added to the mix it is necessary to cast the floor in two courses or the use the colored concrete for the entire one course slab. The dust coat method is more economical since only the top 1/4 of the slab is colored. It usually provides more brilliant colors but it requires careful adherence to the instructions.