ISCC–NBS system

It was first established in the 1930s by a joint effort of the Inter-Society Color Council (ISCC), made up of delegates from various American trade organizations, and the National Bureau of Standards (NBS), a US government agency.

As suggested in 1932 by the first chairman of the ISCC, the system's goal is to be "a means of designating colors in the United States Pharmacopoeia, in the National Formulary, and in general literature ... such designation to be sufficiently standardized as to be acceptable and usable by science, sufficiently broad to be appreciated and used by science, art, and industry, and sufficiently commonplace to be understood, at least in a general way, by the whole public."

The system aims to provide a basis on which color definitions in fields from fashion and printing to botany and geology can be systematized and regularized, so that each industry need not invent its own incompatible color system.

Over the following decades, the ISCC–NBS system's boundaries were tweaked and its relation to various other color standards were defined, including for instance those for plastics, building materials, botany, paint, and soil.

Each of the 267 ISCC–NBS categories is defined by one or more "blocks" within the color solid of the Munsell color system, where each block includes colors falling in a specific interval in hue, value, and chroma, resulting in a shape which "might be called a sector of a right cylindrical annulus (like a piece of pie with the point bitten off)".

Hue relationships between the primary and secondary colors in the ISCC-NBS system of color designation