The CIE 1931 color space chromaticity diagram with wavelengths in nanometers. Note that the colors depicted depend on the color space of the device on which you are viewing the image.

The International Commission on Illumination (usually known as the CIE for its French-language name Commission internationale de l'éclairage) is the international authority on light, illumination, color, and color spaces.

In 1931, the commission developed the CIE 1931 color space, which is still used as a standard reference for defining colors, and as a reference for other color spaces.

The CIE has its headquarters in Vienna, Austria.