A report on Color

Continuous optical spectrum rendered into the sRGB color space.

The upper disk and the lower disk have exactly the same objective color, and are in identical gray surroundings; based on context differences, humans perceive the squares as having different reflectances, and may interpret the colors as different color categories; see checker shadow illusion.

Normalized typical human cone cell responses (S, M, and L types) to monochromatic spectral stimuli

The visual dorsal stream (green) and ventral stream (purple) are shown. The ventral stream is responsible for color perception.

This picture contains one million pixels, each one a different color

The CIE 1931 color space xy chromaticity diagram with the visual locus plotted using the CIE (2006) physiologically-relevant LMS fundamental color matching functions transformed into the CIE 1931 xy color space and converted into Adobe RGB. The triangle shows the gamut of Adobe RGB. The Planckian locus is shown with color temperatures labeled in Kelvins. The outer curved boundary is the spectral (or monochromatic) locus, with wavelengths shown in nanometers. Note that the colors in this file are being specified using Adobe RGB. Areas outside the triangle cannot be accurately rendered since they are outside the gamut of Adobe RGB, therefore they have been interpreted. Note that the colors depicted depend on the gamut and color accuracy of your display.

Additive color mixing: combining red and green yields yellow; combining all three primary colors together yields white.

Subtractive color mixing: combining yellow and magenta yields red; combining all three primary colors together yields black

Visual perceptual property deriving from the spectrum of light interacting with the photoreceptor cells of the eyes.

- Color

41 related topics with Alpha

All colors on this color wheel should appear to have the same lightness and the same saturation, differing only by hue

Hue

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An image with the hues cyclically shifted in HSL space

The hues in this image of a painted bunting are cyclically rotated over time in HSL.

An illustration of the relationship between the "hue" of colors with maximal saturation in HSV and HSL with their corresponding RGB coordinates

Although the variance in luminance is easy to notice for HSL/HSV, the variation in hue is less perceivable. This graph maps 12 points on the HSV color wheel to CIELAB's color plane, displaying the lack of uniformity in hue and saturation.

In color theory, hue is one of the main properties (called color appearance parameters) of a color, defined technically in the CIECAM02 model as "the degree to which a stimulus can be described as similar to or different from stimuli that are described as red, orange, yellow, green, blue, violet," within certain theories of color vision.

Visible spectrum

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Portion of the electromagnetic spectrum that is visible to the human eye.

Newton's color circle, from Opticks of 1704, showing the colors he associated with musical notes. The spectral colors from red to violet are divided by the notes of the musical scale, starting at D. The circle completes a full octave, from D to D. Newton's circle places red, at one end of the spectrum, next to violet, at the other. This reflects the fact that non-spectral purple colors are observed when red and violet light are mixed.

Newton's observation of prismatic colors (David Brewster 1855)

How visible light interacts with objects to make them colorful

Approximation of spectral colors on a display results in somewhat distorted chromaticity

Earth's atmosphere partially or totally blocks some wavelengths of electromagnetic radiation, but in visible light it is mostly transparent

The spectrum does not contain all the colors that the human visual system can distinguish.

Opponent colors based on the NCS experiment. Deuteranopes see little difference between the two colors in the central column.

Opponent process

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Log-log plot of spatial contrast sensitivity functions for luminance and chromatic contrast

The opponent process is a color theory that states that the human visual system interprets information about color by processing signals from cone cells and rod cells in an antagonistic manner.

Comparison of some RGB and CMYK chromaticity gamuts on a CIE 1931 xy chromaticity diagram

Color space

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A comparison of the chromaticities enclosed by some color spaces.

Thomas Young and Hermann Helmholtz assumed that the eye's retina consists of three different kinds of light receptors for red, green and blue

A comparison of CMYK and RGB color models. This image demonstrates the difference between how colors will look on a computer monitor (RGB) compared to how they will reproduce in a CMYK print process.

Additive color mixing: Three overlapping light bulbs in a vacuum, adding together to create white.

Subtractive color mixing: Three splotches of paint on white paper, subtracting together to turn the paper black.

A color space is a specific organization of colors.

Complementary colors

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Complementary colors in the traditional RYB color model.

Colors that are opposite on a color wheel. Complementary colors in the opponent process theory.

In the CMYK color model, the primary colors magenta, cyan, and yellow together make black, and the complementary pairs are magenta–green, yellow–blue, and cyan–red.

A traditional color star developed in 1867 by Charles Blanc. The traditional complementary colors used by 19th-century artists such as Van Gogh, Monet and Renoir are directly opposite each other.

The colors of the RGB color model, which uses combinations of red, green, and blue light on a black screen to create all the colors seen on a computer display or television. Complementary colors are opposite each other.

The HSV color wheel has the same complementary colors as the RGB color model, but shows them in three dimensions.

Newton's color circle (1704) displayed seven colors. He declared that colors opposite each other had the strongest contrast and harmony.

A Boutet color circle from 1708 showed the traditional complementary colors; red and green, yellow and purple, and blue and orange.

The color wheel designed by Johann Wolfgang von Goethe (1810) was based on the idea that the primary colors yellow and blue, representing light and darkness, were in opposition to each other.

Impression, Sunrise by Claude Monet (1872) featured a tiny but vivid orange sun against a blue background. The painting gave its name to the Impressionist movement.

Oarsmen at Chatou by Pierre-Auguste Renoir (1879). Renoir knew that orange and blue brightened each other when put side by side.

In this self-portrait (1889), Vincent van Gogh made the most of the contrast between the orange of his hair and the blue background.

Starry Night by Vincent van Gogh (1889) features orange stars and an orange moon.

The Night Café by Vincent van Gogh (1888) used red and green to express what van Gogh called "the terrible human passions".

Orange life rafts provide the highest contrast and visibility seen against blue water.

Red and cyan glasses are used for viewing Anaglyph 3D three-dimensional images on the Internet or in print.

This image, viewed with red and cyan Anaglyph 3D glasses, will appear in three dimensions.

Complementary colors are pairs of colors which, when combined or mixed, cancel each other out (lose hue) by producing a grayscale color like white or black.

Primary color

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A photograph of the red, green, and blue elements (subpixels) of an LCD. Additive mixing explains how light from these colored elements can be used for photorealistic color image reproduction.

A magnified representation of small partially overlapping spots of cyan, magenta, yellow, and key (black) halftones in CMYK process printing. Each row represents the pattern of partially overlapping ink "rosettes" so that the patterns would be perceived as blue, green, and red when viewed on white paper from a typical viewing distance. The overlapping ink layers mix subtractively while additive mixing predicts the color appearance from the light reflected from the rosettes and white paper in between them.

Color Mixing Guide, John L. King 1925, cover and plates describing yellow, red, and blue color mixing.

A representation of Johannes Itten's color wheel showing his red, yellow, and blue as primary colors within the central equilateral triangle.

An 1896 self-portrait by Anders Zorn clearly showing a four-pigment palette of what are thought to be white, yellow ochre, vermillion, and black pigments.

A conceptual visualization of a color matching experiment. A circular foveal bipartite field (about the size one's thumbnail an arm's length away ) is presented to the observer in a dark surround. One part of the field is illuminated by a monochromatic test stimulus. The participant adjusts the intensities of the three coincident monochromatic primary lights (which are usually red, green and blue hues) on either field until both the test stimulus and match stimulus appear as the exact same color. In this case the participant has added red to the 480 nm test stimulus and has almost matched the match stimulus made of only the green and blue lights of comparable intensities. The specific monochromatic primaries shown here are from the Stiles-Burch 1955 experiment.

The CIE RGB, CIE XYZ color matching functions and LMS cone fundamentals. The curves are all for 2° fields.

Ewald Hering's illustration of the psychological primaries. Red/green and yellow/blue form opponent pairs (top). Each color can be psychologically mixed to make other colors (bottom) with both members of the other pair but not with its opponent according to Hering.

The color scheme of François d'Aguilon, where the two simple colors of white (albus) and black (niger) are mixed to the "noble" colors of yellow (flavus), red (rubeus), and blue (caeruleus). Orange (aureus), purple (purpureus), and green (viridis) are each combinations of two noble colors.

Johann Heinrich Lambert's "Farbenpyramide" tetrahedron published in 1772. Gamboge (yellow), carmine (red), and Prussian blue pigments are used the corner swatches of each "level" of lightness with mixtures filling the others and white at the top.

Philipp Otto Runge's sketch showing bl (blue), g (yellow) and r (red) as the fundamental colors.

A set of primary colours consists of colourants or coloured lights that can be mixed in varying amounts to produce a gamut of colours.

Goethe's color wheel from his 1810 Theory of Colours

Color theory

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Page from 1826 A New Practical Treatise on the Three Primitive Colours Assumed as a Perfect System of Rudimentary Information by Charles Hayter

Munsell's 1905 color system represented as a three-dimensional solid showing all three color making attributes: lightness, saturation and hue.

Chevreul's 1855 "chromatic diagram" based on the RYB color model, showing complementary colors and other relationships

Primary, secondary, and tertiary colors of the RYB color model

The hottest radiating bodies (e.g. stars) have a "cool" color, while the less hot bodies radiate with a "warm" color. (image is in Kelvin scale)

Doppler redshift for receding and blueshift for advancing

Georg Christoph Lichtenberg. Göttingen, 1775, plate III.

Ignaz Schiffermüller, Versuch eines Farbensystems (Vienna, 1772), plate I.

In the visual arts, color theory is a body of practical guidance to color mixing and the visual effects of a specific color combination.

Green

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The notion of "green" in modern European languages corresponds to about 520–570 nm, but many historical and non-European languages make other choices, e.g. using a term for the range of ca. 450–530 nm ("blue/green") and another for ca. 530–590 nm ("green/yellow").

Green, blue and red are additive colors. All the colors seen are made by mixing them in different intensities.

Three green lasers being fired at a single spot in the sky from the Starfire Optical Range

The Chicago River is dyed green every year to mark St. Patrick's Day

Fireworks typically use barium salts to create green sparks

A green light is the universal symbol of permission to go

The chloroplasts of plant cells contain a high concentration of chlorophyll, making them appear green.

Frogs often appear green because light reflects off of a blue underlayer through a yellow upperlayer, filtering the light to be primarily green.

A yellow-naped Amazon parrot, colored green for camouflage in the jungle

The green huntsman spider is green due to the presence of bilin pigments in the spider's hemolymph and tissue fluids

The gardens of ancient Egypt were symbols of rebirth. Tomb painting of the gardens of Amon at the temple of Karnak, from the tomb of Nakh, the chief gardener. Early 14th century BC.

The Ancient Egyptian god Osiris, ruler of the underworld and of rebirth and regeneration, was typically shown with a green face. (Tomb of Nefertari, 1295–1253 BC)

Ancient Roman fresco of Flora, or Spring, from Stabiae (2nd century AD)

In the Arnolfini portrait by Jan van Eyck (1434), the rich green fabric of the dress showed the wealth and status of the family.

Duccio di Buoninsegna painted the faces in this painting (1308–1311) with an undercoat of green earth pigment. The surface pink has faded, making the faces look green today.

The green costume of the Mona Lisa shows she was from the gentry, not from the nobility.

Saint Wolfgang and the Devil, by Michael Pacher.

In this 1503 painting by Perugino, malachite pigment was used to paint the bright green garments of the worshippers, while the background greens were painted in green earth pigments.

Dedham Vale (1802) by John Constable. The paintings of Constable romanticized the vivid green landscapes of England

In the painting of Jean-Baptiste Debret (1822), Emperor Pedro I of Brazil wearing the imperial mantle decorated with green fabric.

In the paintings of Jean-Baptiste-Camille Corot (1796–1875), the green of trees and nature became the central element of the painting, with the people secondary

The Night Café, (1888), by Vincent van Gogh, used red and green to express what Van Gogh called "the terrible human passions."

Émile Bernard – Still life with green teapot, cup and fruit, 1890

Louis Anquetin – Woman at the Champs-Élysées by night

A medieval illustration of a dragon (1460)

A 20th-century depiction of a leprechaun

The green benches in the House of Commons of the United Kingdom

The reverse of the United States one-dollar bill has been green since 1861, giving it the popular name greenback.

The green harp flag was the banner of Irish nationalism from the 17th century until the early 20th century.

The emblem of the Australian Greens. The party won 10% in the 2016 elections for the Australian Senate.

A demonstration by Les Verts, the green party of France, in Lyon.

The Rainbow Warrior, the ship of the Greenpeace environmental movement.

A baccarat palette and cards on a casino gambling table.

A 1929 Bentley colored British racing green.

A billiards table, colored green after the lawns where the ancestors of the game were originally played.

Green is the color between cyan and yellow on the visible spectrum.

The line of purples circled on the CIE chromaticity diagram. The bottom left of the curved edge is violet. Points near and along the circled edge are purple.

Violet (color)

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Five presidents in the oval office. The two more recent presidents, George W. Bush and Barack Obama, are wearing violet ties.

A Japanese woman in the kimono style popular in the Heian period (794–1185) with a violet head covering.

The Susan B. Anthony stamp (1936), was the reddish tone of purple sometimes known as red-violet since violet was a color that represented the Women's Suffrage movement.

In amethyst, the violet color arises from an impurity of iron in the quartz.

Chemical structure of pigment violet 29. Violet pigments typically have several rings.

Manganese violet, a popular inorganic pigment.

The marine hatchetfish (here eating a small crustacean) lives in extreme depths.

The violet carpenter bee (Xylocopa violacea) is one of the largest bees in Europe.

The violet-backed starling is found in Sub-Saharan Africa.

The violet sabrewing is found in Central America.

The imperial amazon parrot is featured on the national flag of Dominica, making it the only national flag in the world with a violet color.

The iris flower takes its name from the Greek word for rainbow.

Lavender fields in the Vaucluse, in Provence, France

alt=Wisteria blooms are a light violet color.|Wisteria blooms are a light violet color.

The Wilton Diptych (1395), painted for King Richard II.

A violet-clad angel from the Resurrection of Christ by Raphael (1483–1520).

Charles de Bourbon, the future King Carlos III of Spain (1725).

In England, pre-Raphaelite painters like Arthur Hughes were particularly enchanted by purple and violet. This is April Love (1856).

Nocturne: Trafalgar Square Chelsea Snow (1876) by James McNeill Whistler, used violet to create a wintery mood.

The Starry Night, by Vincent van Gogh (1889), Museum of Modern Art.

Violet is the color of light at the short wavelength end of the visible spectrum, between blue and invisible ultraviolet.

CIE xy chromaticity diagram
The spectrum colors are the colors on the horseshoe-shaped curve on the outside of the diagram. All other colors are not spectral: the bottom line is the line of purples, whilst within the interior of the diagram are unsaturated colors that are various mixtures of a spectral color or a purple color with white, a grayscale color. White is in the central part of the interior of the diagram, since when all colors of light are mixed together, they produce white.

Spectral color

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This metrically accurate diagram shows that the spectral locus is almost flat on the red – bright green segment, is strongly curved around the green, and becomes less curved between green/cyan and blue

A spectral color is a color that is evoked in a typical human by a single wavelength of light in the visible spectrum, or by a relatively narrow band of wavelengths, also known as monochromatic light.