Integral color is a term applied to the technique wherein the color is introduced while the concrete is still in a plastic state. This includes coloring agents affecting the cement paste, decorating aggregates and combinations of these two. Practically all coloring of cement pastes is achieved with synthetic or natural pigments. The choice of which one to use should be based upon several factors. Natural pigments are low in cost and when a medium shade is desired, they might prove most economical and practical. Unfortunately, their coloring power works only to a certain point, depending on the ore, after which further additions will only lighten the shade. Synthetic oxide pigments can be used to obtain practically any desired shade. Also, the range of colors in synthetic pigments is considerable broader than in their natural counterparts. Another factor in favor of synthetic pigments is that they can be ground finer. This gives them from two to five times greater tinctorial power than natural pigments. If pigments are to be mixed in the concrete, they are usually batched (always by weight, not volume) dry with the aggregates and cement, mixed and then the water is added and the entire batch is given its final mixing. Another means of attaining colored concrete is by the dusting technique. For this procedure, sprinkle the pigment mixture evenly over the surface to be colored only after all puddles and surface water have evaporated. Then trowel to a smooth finish making sure that no water is brought to the surface. Exposing decorative aggregates in the surface of concrete, while not a new development, has gained great popularity recently in the move toward more colorful structures. The technique has several advantages. One, it is easier to predict more accurately what the finished product will look like and the colors are usually longer lasting. Also, the availability of a wide choice of colors is another important advantage. A simple method for exposing decorative aggregates is the scattering or broadcast method. In this approach, the slab is cast in the usual manner with a white or colored topping. After the concrete has hardened sufficiently to support a man and leave only slight heel indentations, the decorative aggregate is broadcast over the surface of the slab. The aggregate must be applied thickly and evenly to avoid any spotty effect. The surface is then lightly rolled to assure a good bond of the aggregate with the concrete. The technique is economical since it is simple and rapid and because only minimum amount of decorative aggregate is necessary.