Staining the top of concrete is quick, easy and effective. However, the color only stains the top layer and it will wear and discolor after extensive use. Mixing the color into the concrete before it is poured is the only sure way of a consistent permanent color. Even if the concrete chips, the color underneath is still the same.
The coloring powders to mix into concrete are manufactured by a number of companies. Their color charts showing what hues are available help a contractor determine the final color of the concrete. The colors normally come very close to the desired outcome, but it may not match absolutely. Each concrete manufacturer has its own list of ingredients, which affects how the coloring powder reacts with the other chemicals.
Because the mixture of material in concrete is not always consistent from load to load, the only way to ensure a matching color is to mix it all in one load. If two or more loads are needed it is important to keep the combinations of ingredients as similar to one another as possible.
Homeowners can add color to small, wheelbarrow sized batches by using a 5-lb. bag of color agent with a standard 96-lb. bag of concrete. Approximately 1/3 of the necessary water is added to the concrete along with the entire bag with the coloring powder. The bag dissolves into the water as the concrete is mixed and adds the color to the material. The remaining water is then added to smooth out the concrete mix and give it the consistency of a stiff cake batter.