Color science in the context of Chromaticity

Color reproduction is an aspect of color science concerned with producing light spectra that evoke a desired color, either through additive (light emitting) or subtractive (surface color) models. It converts physical correlates of color perception (CIE 1931 XYZ color space tristimulus values and related quantities) into light spectra that can be experienced by observers. In this way, it is the opposite of colorimetry.

It is concerned with the faithful reproduction of a color in one medium, with a color in another, so it is a central concept in color management and relies heavily on color calibration. For example, food packaging must be able to faithfully reproduce the colors of the foods therein in order to appeal to a customer. This involves proper color calibration of at least four devices:

In radiometry, photometry, and color science, a spectral power distribution (SPD) measurement describes the power per unit area per unit wavelength of an illumination (radiant exitance). More generally, the term spectral power distribution can refer to the concentration, as a function of wavelength, of any radiometric or photometric quantity (e.g. radiant energy, radiant flux, radiant intensity, radiance, irradiance, radiant exitance, radiosity, luminance, luminous flux, luminous intensity, illuminance, luminous emittance).

Knowledge of the SPD is crucial for optical-sensor system applications. Optical properties such as transmittance, reflectivity, and absorbance as well as the sensor response are typically dependent on the incident wavelength.

In color science, 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. It differs from a color space in that a color model is not absolute, that is, there is no way to map a color within a color model to a point in a color space.

This article describes ways in which human color vision can be modeled, and discusses some of the models in common use.

A secondary color is a color made by mixing two primary colors of a given color model in even proportions. Combining one secondary color and a primary color in the same manner produces a tertiary color. Secondary colors are special in traditional color theory and color science.

Color theory, or more specifically traditional color theory, is a historical body of knowledge describing the behavior of colors — namely in color mixing, color contrast effects, color harmony, color schemes and color symbolism. Modern color theory is generally referred to as color science. While they both study color and its existence, modern or "traditional" color theory tends to be more subjective and have artistic applications, while color science tends to be more objective and have functional applications, such as in chemistry, astronomy or color reproduction. However, there is much intertwining between the two throughout history, and they tend to aid each other in their own evolutions.

Though, color theory can be considered a science unto itself that uses the relationship between human color perception and the interactions of colors together to build their palettes, schemes, and color mixes. Importantly, color theory relies upon objective standards in-order to be consistent in color mixing and presentation - i.e. to achieve the ideal color and effect, your ratios of colors must be consistent and often exact. As for functional applications, color theory intandem with color science is what allows humans to achieve ideal camouflage, designed paints that disperse more heat, and is often used by theme parks like Disney to achieve their ideal aesthetic.

Chromaticity is an objective specification of the quality of a color regardless of its luminance. Chromaticity consists of two independent parameters, often specified as hue (h) and colorfulness (s), where the latter is alternatively called saturation, chroma, intensity, or excitation purity. This number of parameters follows from trichromacy of vision of most humans, which is assumed by most models in color science.

In color science, color difference or color distance is the separation between two colors. This metric allows quantified examination of a notion that formerly could only be described with adjectives. Quantification of these properties is of great importance to those whose work is color-critical. Common definitions make use of the Euclidean distance in a device-independent color space.

In color science, a color gradient (also known as a color ramp or a color progression) specifies a range of position-dependent colors, usually used to fill a region.

In assigning colors to a set of values, a gradient is a continuous colormap, a type of color scheme.In computer graphics, the term swatch has come to mean a palette of active colors.