A system for describing color numerically. Also known as a "color model," the most widely used color spaces are RGB for scanners, cameras and displays, CMYK for color printing and YUV for TV/video. Prior to the proliferation of electronic displays, which are all RGB, color spaces were developed that were closer to the way people think about color. For example, the CIE Lab model uses lightness (L) and values on red-green (a) and blue-yellow (b) axes, while HSB uses hue, saturation and brightness. See CIE Lab, HSB, HSL, RGB, sRGB, YUV, xvYCC and color space conversion.