Color name

A color name is a linguistic label that humans attach to a color. Such a color is determined by a physical color and/or some other physical features like reflection or iridescence. Sometimes naming of colors is limited only to describe the feature of a physical color.

Naming of colors is dependent on a specific language. There can be a vast and complex system representing determination of a color in a given language. Generally, naming of colors involves a vocabulary and a grammatical syntax.

As the color space is continuous, naming of colors involves quantization, often by a vocabulary that specifies gradual change of one color into another. For example, let us discuss the so called HSI color space, where each color has attached its numerical values of hue, saturation and intensity, which is enough to determine any color as defined in physics, perceived by a human. Each of the values can gradually change. Thus, gradual change of hue can be described for example by names like red, orange red, orange, yellowish orange, yellow, green yellow, green, sea green, cyan, blue, violet and purple. Gradual change of saturation may for example be expressed by adding to a color name labels like gray, grayish, moderate, strong and vivid. Gradual change of intensity may be expressed by adding labels like for example blackish, very dark, dark, medium, light and very light. Because such a way of naming colors can lead to relatively long names, shortcuts like pastel for a color that is both light and moderately saturated, or descriptive names like olive (color) for relatively dark, yellowish green, are used. Naming of colors goes outside determining just a physical color. For example, silver describes a glistening surface that does not modify proportions in spectrum of the reflected light or in other words does not modify hue of the light, while golden describes a glistening surface that reflects mainly yellow light. Special kinds of reflection give names to terms like sparkling, metallic, alluminium, i. e. green metallic, and various forms of scattering, dispersion and diffraction of light by a surface may add to a color name terms like opalescent or iridescent.

A system of naming colors can be hierarchical. For example, a coarse categorization of saturated colors may divide the colors into red, yellow, green, blue and violet. Yet, within such a category, finer categories can be determined, i. e. within green sea green and olive can be identified. A finer category may belong to two categories at once, i. e. orange is a set of colors between red and yellow, that can be quantized into red and yellow.

Regularity

A study conducted by Berlin and Kay, 1969 has shown that there are substantial regularities in naming colors across many different languages. In the study, a concept of the following basic color terms has been identified: black, grey, white, pink, red, orange, yellow, green, blue, purple and brown. It is known, however, that there can be also significant differences between naming colors in different languages and cultures. For example, a kind of sea green, called aoi in Japanese, in English is generally regarded as a shade of green, while in Japanese what an English speaker would identify as "green" can be regarded as a different shade of the kind of sea green.

Every natural language that has words for colors identifies between 2 and 11 "basic" colors (for example, English has 11, namely the colors listed above). All other colors are considered by most speakers of that language to be variants of these basic colors. While the tremendous range in the number of basic colors between languages may seem to highlight a striking difference, there is almost without exception a pattern to how these colors are included among the basic colors. As might be expected, languages with two basic colors identify black and white. Red is almost always next, followed by either green or blue. After this, the patterns are more complex, and Berlin and Kay's original results have had to be extended on more than one occasion to accommodate new data. However, many sociolinguists still agree that these patterns exist.

See also Whorf-Sapir hypothesis

Standardized systems

A computational system of naming colors can be quite complex, because human perceives a color and names it in a complex way. For example, in the discussed HSI color space decreasing the intensity of yellow may change the color into dark green, instead of dark yellow. As an another example, a given color can be pink for one subject and purple for another subject. One of the ways of reducing such inconsistences may be asking a number of subjects about naming a set of colors and then deriving, on basis of their answers and of a linguistic study on human color categorization, a computational model that determines a color name, possibly at a required detail level, by the position of the color in a color space.

Some examples of color naming systems are Munsell system and ISCC-NBS lexicon of color names. The disadvantage of the systems, however, is the lack of an exact computational model of attaching a name to a given color sample. There are also several color naming systems that have such a computational model, yet they oversimplify the interpretation of the HSI or HSV color spaces.

See also: X11 color names, Crayola 64pt:Nome das cores