- Light of different wavelkengths (and so different colours)
- Powder paints
- Acrilic paints
- Industrial paints
A colour model is
- A basic RGB colour model does not define the precise wavelengths of the red, green and blue components. When the exact chromaticity (hue + saturation – chromaticity) of each primary colour is defined, the colour model then becomes an absolute colour space, such as sRGB or Adobe RGB.
- Trichromatic colour wheels explore additive colour and subtractive colour models using sets of primary colours.
A color model is an abstract mathematical model describing the way colors can be represented as tuples of numbers (e.g. three tuples in RGB or four in CMYK), however a color model with no associated mapping function to an absolute color space is a more or less arbitrary color system with no connection to any globally understood system of color interpretation. Adding a specific mapping function between a color model and a reference color space establishes within the reference color space a definite “footprint”, known as a gamut, and for a given color model this defines a color space. For example,Adobe RGB and sRGB are two different absolute color spaces, both based on the RGB color model. When defining a color space, the usual reference standard is the CIELAB or CIEXYZ color spaces, which were specifically designed to encompass all colors the average human can see.
Since “color space” is a more specific term, identifying a particular combination of color model and mapping function, it tends to be used informally to identify a color model, since identifying a color space automatically identifies the associated color model, however this usage is strictly incorrect. For example, although several specific color spaces are based on the RGB color model, there is no such thing as the singular RGB color space.