## Colour space

A colour space is based on a colour model, and is its concrete application to a colouring method (printer, monitor, etc). It therefore contains all colours that can actually be represented through this method and the associated materials.

For example, sRGB and AdobeRGB are both colour spaces based on the RGB colour model. They can only represent a portion of the colours theoretically defined by the RGB model.

## Colour system

A colour system (or colour model) is an abstract mathematical method for determining and specifying colours and their relationship to each other.
It is sometimes referred to as colour space, although the latter is the concrete application of a colour model to a colour-producing method (printer, monitor, etc.).

Well-known colour systems are:

• RGB (additive colour mixing with red, green and blue)
• CMYK (subtractive colour mixing with cyan, magenta, yellow and black)
• Lab/CIELab (brightness, red-green axis and blue-yellow axis)
• HSL and HSB/HSV (Hue, Saturation, Lightness and Hue, Saturation, Brightness/Value)

## Colour model

A colour model (or colour system) is an abstract mathematical method for determining and specifying colours and their relationship to each other.
It is sometimes referred to as colour space, although the latter is the concrete application of a colour model to a colour-producing method (printer, monitor, etc.).

Well-known colour models are:

• RGB (additive colour mixing with red, green and blue)
• CMYK (subtractive colour mixing with cyan, magenta, yellow and black)
• Lab/CIELab (brightness, red-green axis and blue-yellow axis)
• HSL and HSB/HSV (Hue, Saturation, Lightness and Hue, Saturation, Brightness/Value)

## Gamut mapping

The conversion of colour values from one colour space (e.g. sRGB on the monitor) to another colour space (e.g. CMYK in print) so that the colour reproduction remains as consistent as possible.

## Colour gamut

The colour gamut (or simply: gamut) refers to the range of all colours in a colour space that can be recognised (camera, scanner) or reproduced (printer, monitor) by a device.
It is visualised in the form of a colour solid.

## Colour location

The colour location describes the position of a measured or selected colour within a colour space. This is often defined by coordinates, e.g. using L, a and b in the CIELab colour space.
The set of all the colour locations in a colour space is called the colour gamut (or gamut).

## sRGB

sRGB is the most widely used RGB colour space, and was created for monitors by Hewlett-Packard and Microsoft in 1996. sRGB is the standard colour space of all inexpensive digital cameras and scanners. Nearly every 8-bit RGB file without profile identification corresponds to sRGB.

Intel, Pantone, Corel and numerous other companies rely on sRGB or have implemented the colour space as standard. Today sRGB is no longer popular in the printing industry, as the colour space is sometimes much smaller than the printable colour range of ISOCoatedV2 and therefore partially restricts the printable colours. Colour spaces such as AdobeRGB 1998 or ECI-RGB V2, which are optimized for printing, are therefore also preferred today for image processing in RGB.

## Gamut

The gamut (also colour gamut) refers to the range of all colours in a colour space that can be recognised (camera, scanner) or reproduced (printer, monitor) by a device.
It is visualised in the form of a colour solid.