The measurement of color is an industrially important but often unrecognized branch of analytical chemistry, as the papers to follow demonstrate. Like most analytical procedures, color measurement can be divided into two basic steps: examination (LOOK) and assessment (THINK). In industrial practice, the LOOK step usually consists of comparing a colored sample to a standard. Whether the colorist LOOKS by eye or with the aid of an instrument makes no essential difference. What are important, and are often overlooked, are: (1) the statistical nature of both types of measurement, and the need for taking their inherent errors into account; and (2) the need for utilizing a statistically valid sample, presented in a form suitable for measurement. The THINK step in color measurement consists of: (1) recognizing the existence (if any) and nature of the difference between sample and standard; (2) describing the difference in standardized, accepted verbal or numerical terminology; and (3) evaluating the significance of the result. Each of these steps is an essential part of any analytical procedure, but again, is all too often taken for granted.