An absolute color space is a A color model is an abstract mathematical model describing the way colors can be represented as tuples of numbers, typically as three or four values or color components (e. ...color space in which colors are unambiguous, where they do not depend on any external factors.

An example of an absolute color space is CIE L*a*b* (CIELAB) is the most complete color model used conventionally to describe all the colors visible to the human eye. ...L*a*b*. A L*a*b* color defines an exact color. A L*a*b* color is abstract, but if reproduced using an accurate device and viewed in the right conditions, it should look exactly as intended.

A counter_example of a color space that is not absolute is The RGB color model utilizes the additive model in which red, green, and blue light are combined in various ways to create other colors. ...RGB. RGB is made by mixing red, green and blue, but these are not standardised, precise definitions. Two computer monitors or other RGB devices may show the same RGB image looking very different.

One way to think of this is that L*a*b* is a color, while RGB is a recipe; the results of mixing RGB depend on the ingredients.

A non_absolute color space can be made absolute by defining its ingredients more precisely. For instance, if the red, green and blue colors in a monitor are measured exactly, together with other properties of the monitor, then RGB values on that monitor can now be considered as absolute.

A popular way to make a color space like RGB into an absolute color is to define an ICC profile, which contains the attributes of the RGB. This is not the only way to express an absolute color, but it is the standard in many industries. RGB colors defined by widely accepted profiles include The title given to this article is incorrect due to technical limitations. ...sRGB and The Adobe RGB color space is an RGB color space developed by Adobe Systems in 1998. ...Adobe RGB. The process of adding an ICC profile to a graphic or document is sometimes called tagging; tagging therefore marks the absolute meaning of colors in that graphic or document.

Conversion

One absolute color can be converted to another absolute color, and back again, in general; however, each color space has its own In computer graphics, the gamut, or color gamut, is a certain complete subset of colors. ...gamut, and converting colors that lie outside that gamut will not produce correct results. There are also likely to be rounding errors, especially if the popular range of only 256 distinct values per component (8 bits) is used.

Also note that one part of the definition of an absolute color is the viewing conditions. The same color, viewed under different natural or artificial lighting conditions, will look different. Those involved professionally with color matching may have viewing rooms, lit by standardised lighting.

Occasionally, there are precise rules for converting between non_absolute color spaces. For example The HLS color space, also called HSL, stands for Hue, Saturation, Lightness. While HSV (Hue, Saturation, Value) can be viewed graphically as a color cone or hexcone, HSL is drawn as a double cone or double hexcone. ...HLS is defined as a mapping of RGB. Both are non_absolute, but the conversion between them should maintain the same color. However, in general, converting between two non_absolute color spaces (e.g. RGB to Cyan, magenta, yellow, and key (black) CMYK (or sometimes YMCK) is a subtractive color model used in color printing. ...CMYK) or between absolute and non_absolute color spaces (e.g. RGB to L*a*b*) is almost a meaningless concept, though there will be formulae that give roughly equivalent results.

Other absolute color spaces

A different method of defining absolute color spaces is familiar to many consumers as the swatch card, used to select e.g. paint or fabrics. This is a way of agreeing a color between two parties. A more standardised, but still proprietary, method of defining absolute colors is Pantone Inc. ...Pantone, which includes swatch cards and recipies that commercial printers can use to make inks that are a particular color.