The methods of appraising colors have gone from art to science in just the past few years, and the concrete industry finally has the opportunity to take advantage of it. Today, the measurement of color can be handled as simplistically as the measurement of dimensional tolerances. The device used is called a spectrophotometer (or colorimeter).
Many different types of color measuring instruments are available. A basic colorimeter that can measure the color difference between two objects can be purchased for a few hundred dollars. Hand-held spectrophotometers start at about $3,000. Some systems can store color data in their own memory or can be linked to a computer for data storage and retrieval.
Most colors can be achieved in several ways. Some mixtures will be cheaper than others. The advantage of a computerized spectrophotometer is that it can not only match colors, but, given the proper data, can calculate which method of mixing is least expensive.