Black in the context of "Black-and-white dualism"

Complementary colors are pairs of colors which, when combined or mixed, cancel each other out (lose chroma) by producing a grayscale color like white or black. When placed next to each other, they create the strongest contrast for those two colors. Complementary colors may also be called "opposite colors".

Which pairs of colors are considered complementary depends on the color model that one uses:

Mourning is the emotional expression in response to a major life event causing grief, especially loss. It typically occurs as a result of someone's death, especially a loved one.

The word describes a complex of behaviors in which the bereaved participate or are expected to participate, the expression of which varies by culture. Wearing black clothes is one practice followed in many countries, though other forms of dress are seen. Those most affected by the loss of a loved one often observe a period of mourning, marked by withdrawal from social events and quiet, respectful behavior in some cultures, though in others mourning is a collective experience. People may follow religious traditions for such occasions.

White is the lightest color and is achromatic (having no chroma). It is the color of objects such as snow, chalk, and milk, and is the opposite of black. White objects fully (or almost fully) reflect and scatter all the visible wavelengths of light. White on television and computer screens is created by a mixture of red, blue, and green light. The color white can be given with white pigments, especially titanium dioxide.

In ancient Egypt and ancient Rome, priestesses wore white as a symbol of purity, and Romans wore white togas as symbols of citizenship. In the Middle Ages and Renaissance a white unicorn symbolized chastity, and a white lamb sacrifice and purity. It was the royal color of the kings of France as well as the flag of monarchist France from 1815 to 1830, and of the monarchist movement that opposed the Bolsheviks during the Russian Civil War (1917–1922). Greek temples and Roman temples were faced with white marble, and beginning in the 18th century, with the advent of neoclassical architecture, white became the most common color of new churches, capitols, and other government buildings, especially in the United States. It was also widely used in 20th century modern architecture as a symbol of modernity and simplicity.

Purple is a color similar in appearance to violet light. In the RYB color model historically used in the arts, purple is a secondary color created by combining red and blue pigments. In the CMYK color model used in modern printing, purple is made by combining magenta pigment with either cyan pigment, black pigment, or both. In the RGB color model used in computer and television screens, purple is created by mixing red and blue light in order to create colors that appear similar to violet light. According to color theory, purple is considered a cool color.

Purple has long been associated with royalty, originally because Tyrian purple dye—made from the secretions of sea snails—was extremely expensive in antiquity. Purple was the color worn by Roman magistrates; it became the imperial color worn by the rulers of the Byzantine Empire and the Holy Roman Empire, and later by Roman Catholic bishops. Similarly in Japan, the color is traditionally associated with the emperor and aristocracy.

Brown is a color. It can be thought as a darker, and usually desaturated, shade of orange. In the CMYK color model used in printing and painting, brown is usually made by combining yellow, magenta, and black inks (these two last in a lesser amount).

In the RGB color model used to project colors onto television screens and computer monitors, brown is the result of combining red light at low intensity, and green light at an even lower intensity, with blue light also being present in most shades of the color. The color brown is seen widely in nature, wood, soil, human hair color, eye color and skin pigmentation. Brown is the color of dark wood or rich soil.

The Natural Colour System (NCS) is a proprietary perceptual color model. It is based on the color opponency hypothesis of color vision, first proposed by German physiologist Ewald Hering. The current version of the NCS was developed by the Swedish Colour Centre Foundation, from 1964 onwards. The research team consisted of Anders Hård, Lars Sivik and Gunnar Tonnquist, who in 1997 received the AIC Judd award for their work. The system is based entirely on the phenomenology of human perception as opposed to color mixing. It is illustrated by a color atlas, marketed by NCS Colour AB in Stockholm.

Black-and-white (B&W or B/W) images combine black and white to produce a range of achromatic brightnesses of grey. It is also known as greyscale in technical settings.

Variations of gray or grey include achromatic grayscale shades, which lie exactly between white and black, and nearby colors with low colorfulness. A selection of a number of these various colors is shown below.