AbstractThe field of colorimetry appears to be arbitrarily divided into two areas, matching‐and‐formulation colorimetry and image‐reproduction colorimetry. It is believed that the end uses for the colorimetric data and the methods of color generation are sufficiently different in these two areas to warrant this division. Conditions that contribute to this division are the need for metamerism and the use of limited sets of primaries in reproduction work, the compromise of lightnesses due to tone reproduction, the availability and proper use of instrumentation compared to that desired, and the viewing conditions of the standard observer. All these contribute to produce significantly larger color differences in image‐reproduction work than in matching and formulation. However, workers in reproduction studies can still draw useful conclusions when these conditions are properly understood.