One of the central accomplishments of cognitive anthropology is Berlin and Kay’s (1969) demonstration that the diversity of human color systems is built on a universal infrastructure, with black and white the most basic colors. Their analytical focus is a structural system divorced from the messy tasks of actually using color terms to make relevant distinctions within specific courses of action, situated within the concrete settings that constitute the lifeworld of a particular society. By way of contrast, the last two chapters have argued that categories are intrinsically forms of co-operative action that require a cohort of skilled actors within a community. Analysis here focuses on chemists attempting to determine when to stop a reaction by deciding when the material they are working with is jet black. This chapter explores (1) the diverse practices they use to establish what can count as black, (2) how such a distinction is embedded within the local activity system of a community, and (3) the construction of competent actors through embodied apprenticeship. For the chemists, jet black is not a preformulated, context-free universal color category, but instead a problematic judgment to be artfully accomplished through a collection of systematic work practices.

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