Colorspace

A colorspace is a specific organization of colors used to encode color information in images, displays, and prints. It is defined by a color model and a concrete mapping from numerical values to physical colors, typically specifying a set of primaries, a white point, and a transfer function or gamma. A colorspace fixes the gamut—the range of representable colors—and how brightness and chromaticity are encoded for storage, processing, and rendering.

Primaries and white point determine the gamut of a colorspace. Device-dependent spaces, such as sRGB, Adobe RGB, or CMYK spaces, depend on particular devices or workflows. Device-independent spaces, such as CIELAB and CIELUV, are designed to be perceptually uniform and are commonly used as reference or profile connection spaces in color management.

Color management systems use transformations between colorspaces, often via ICC profiles that describe how to convert colors for a given device or workflow. In this framework, an intermediate or profile connection space, typically CIE XYZ or CIE Lab, is used to convert from a source space to a destination space. Perceptual consistency under varying viewing conditions can be addressed with color appearance models, which adjust for viewing environment and adaptation.

The terms colorspace and color profile are related but not identical: a profile documents the characteristics of a colorspace on a device, facilitating accurate translation across devices and applications. See also color model, gamut, ICC profile, color management, and profile connection space.