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.

In color theory, two colors are called complementary if, when mixed in the proper proportion, they produce a neutral color (grey, white, or black).

In roughly-perceptual color models, the neutral colors (white, greys, and black) lie along a central axis. For example, in the HSV color space, complementary colors (as defined in HSV) lie opposite each other on any horizontal cross-section.

Thus, in the CIE 1931 color space a color of a particular "dominant" wavelength can be mixed with a particular amount of the "complementary" wavelength to produce a neutral color (grey or white).

In the RGB color model (and derived models such as HSV), primary colors and secondary colors are paired in this way:

When one stares at a single color (red for example) for a sustained period of time (roughly thirty seconds to a minute), then looks at a white surface, an afterimage of the complementary color (in this case cyan) will appear. This is one of several aftereffects studied in the psychology of visual perception which are generally ascribed to fatigue in specific parts of the visual system.

A Love (사랑 - Sarang) is a 2007 South Korean film directed by Kwak Kyung-taek. Kwak Kyung-taek's most notable film is Chingoo. A Love stars Ju Jin-mo from 200 Pounds Beauty and Park Si-yeon.

At age 17, In ho meets a girl as beautiful as a watercolor painting, and promises to protect her after her brother dies. Although he is the best fighter in his school, he dreams of making his mother proud by going to college. It takes him 7 years to confess to the girl of his dreams. He stabs a gangster in the neck for her, although he wanted to live quietly like everyone else. But to keep his promise to protect her, he stabs Chi-kwon, a notorious mobster in Busan. He devotes his life to working for Chairman Yoo. He buries his love for the vanished girl and gets a second chance while working at the docks. He offers his life to the man who first holds out his hand for him. The girl he cannot forget returns as a love he cannot have. She becomes his patron’s woman and beyond reach... But as he decides to be happy for once in life, cruel destiny rattles everything in his life.

In the visual arts, color theory is a body of practical guidance to color mixing and the visual impacts of specific color combination. There are also definitions (or categories) of colors based on the color wheel: primary color, secondary color and tertiary color. Although color theory principles first appeared in the writings of Leone Battista Alberti (c.1435) and the notebooks of Leonardo da Vinci (c.1490), a tradition of "colory theory" began in the 18th century, initially within a partisan controversy around Isaac Newton's theory of color (Opticks, 1704) and the nature of so-called primary colors. From there it developed as an independent artistic tradition with only superficial reference to colorimetry and vision science.

The foundations of pre-20th-century color theory were built around "pure" or ideal colors, characterized by sensory experiences rather than attributes of the physical world. This has led to a number of inaccuracies in traditional color theory principles that are not always remedied in modern formulations.^{[citation needed]}