Nuluce - Web Design - Color Theory Quick Reference Guide

Color Theory Quick Reference Guide

Posted: 2011-05-13 by David Hatchard

Color Theory Quick Reference GuideSubtractive and Additive Color

A subtractive color model explains the mixing of paints, dyes, inks, and natural colorants to create a full range of colors, each caused by subtracting (that is, absorbing) some wavelengths of light and reflecting the others. The color that a surface displays depends on which colors of the electromagnetic spectrum are reflected by it and therefore made visible.

Subtractive color systems start with light, presumably white light. Colored inks, paints, or filters between the viewer and the light source or reflective surface subtract wavelengths from the light, giving it color. If the incident light is other than white, our visual mechanisms are able to compensate well, but not perfectly, often giving a flawed impression of the "true" color of the surface.

Conversely, additive color systems start without light (black). Light sources of various wavelengths combine to make a color. In either type of system, three primary colors are combined to stimulate humans’ trichromatic color vision, sensed by the three types of cone cells in the eye, giving an apparently full rang

Color Types

Primary colors: are sets of colors that can be combined to make a useful range of colors. For human applications, three primary colors are usually used, since human color vision is trichromatic.

For additive combination of colors, as in overlapping projected lights or in CRT displays, the primary colors normally used are red, green, and blue. For subtractive combination of colors, as in mixing of pigments or dyes, such as in printing, the primaries normally used are cyan, magenta, and yellow, though the set of red, yellow, blue is popular among artists. See RGB color model, CMYK color model, and RYB color model for more on these popular sets of primary colors.

Any choice of primary colors is essentially arbitrary; for example, an early color photographic process, autochrome, typically used orange, green, and violet primaries. However, unless negative amounts of a color are allowed the gamut will be restricted by the choice of primaries.

The combination of any two primary colors creates a secondary color.

The most commonly used additive color primaries are the secondary colors of the most commonly used subtractive color primaries, and vice versa.

Secondary Colors: A secondary color is a color made by mixing two primary colors in a given color space.

Tertiary Colors: A tertiary color is a color made by mixing one primary color with one secondary color, in a given color space such as RGB or RYB.

Unlike primary and secondary colors, these are not represented by one firmly established name each, but the following examples include some typical names. Brown and grey are sometimes known as Tertiary colors and can be made by mixing complementary colors.

Complementary Colors: Complementary colors are pairs of colors that are of “opposite” hue in some color model. The exact hue “complementary” to a given hue depends on the model in question, and perceptually uniform, additive, and subtractive color models, for example, have differing complements for any given color.

Analogous Colors: or analogous hues Closely related hues, especially those in which we can see a common hue; hues that are neighbors on the color wheel, such as blue, blue-green, and green.

Color Symbolism

Color symbolism refers to the meaning associated with that a certain color. Each color may have several different color symbolisms attached to it depending on the context and culture it is used in. (For example, white in some cultures symbolizes purity. In other cultures, it symbolizes death.) There are a number of influential factors that affect the symbolism of a color.

These influences include the following:

  1. The different shades of a color (like red and pink).
  2. The object or shape the color is contained within.
  3. The position and amount of the color in an area.
  4. The color combination used (such as red, white and blue, or red and green). When color is used in a large region or shape, it can have a strong impact in its symbolism. Moreover, when a color is used along with a certain shape – such as a star, triangle, or hexagon – the symbolism of the color becomes more complex.