White cement may be necessary to achieve maximum color clarity or delicate shades. Other cements may be used to achieve special effects. Similarly, the concrete aggregates should be selected with consideration of their effect on color. The fine aggregate can have an especially significant effect. Colored concrete requires control of water and mixing procedures used.
Excess water can cause the color to look pale and weak.
Add color at the same point during mixing for all batches. Generally, dry pigments should be mixed with the cement and aggregate before the addition of water. Assure that the batching, mixing, and placing practices are constant throughout the job. Do not use calcium chloride set accelerators with concrete colors since discoloration can result. The amount of colorant used depends upon the desired effect and mix characteristics.