A color gamut is a subset of colors, usually representing the colors that a display or a printing device can represent.
No display or printer can represent the whole range of colors that a human eye can perceive. The device gamut represents the set that it supports.
Traditionally, in web development, the only gamut used was sRGB (Standard Red-Green-Blue), where each color is described using three bytes, one for each primary color. However, "wide-color" monitors and professional printers support a wider range of colors, that can't be represented using this gamut.
Developers can define different sets of colors for devices supporting larger gamuts using the
color-gamut media feature. They can describe colors outside the RGB gamut using specific CSS functions like
lch() for the LCH cylindrical coordinate system, or
lab() for the Lab coordinate system.
- Gamut on Wikipedia.