Green
— Spectral coordinates —
Wavelength		520–570 nm
Frequency		~575–525 THz
— Common connotations —
nature, growth, grass, hope, youth, inexperience, sickness, health, Islam, spring, Saint Patrick's Day, money (US), greed, and envy[1][2][3]
— Color coordinates —
Hex triplet		#00FF00
sRGBB	(r, g, b)	(0, 255, 0)
Source		sRGB approximation to NCS S 2060-G[4]
B: Normalized to [0–255] (byte)

Green is a color, the perception of which is evoked by light having a spectrum dominated by energy with a wavelength of roughly 520–570 nanometers. In the subtractive color system, it is not a primary color, but is created out of a mixture of yellow and blue, or yellow and cyan; it is considered one of the additive primary colors. On the HSV color wheel, also known as the RGB color wheel, the complement of green is magenta; that is, a purple color corresponding to an equal mixture of red and blue light. On a color wheel based on traditional color theory (RYB), the complementary color to green is considered to be red.^[5]

The word green is closely related to the Old English verb growan, "to grow". It is used to describe plants or the ocean. Sometimes it can also describe someone who is inexperienced, jealous, or sick. In the United States of America, green is a slang term for money, among other things. Several colloquialisms have derived from these meanings, such as "green around the gills", a phrase used to describe a person who looks ill.

Several minerals have a green color, including emerald, which is colored green by its chromium content. Animals such as frogs, lizards, and other reptiles and amphibians, fish, insects, and birds, appear green because of a mixture of layers of blue and green coloring on their skin. By far the largest contributor to green in nature is chlorophyll, the chemical by which plants photosynthesize. Many creatures have adapted to their green environments by taking on a green hue themselves as camouflage.

Culturally, green has broad and sometimes contradictory meanings. In some cultures, green symbolizes hope and growth, while in others, it is associated with death, sickness, envy, or the devil, or both, depending on the context. The most common associations, however, are found in its ties to nature. For example, Islam venerates the color, as it expects paradise to be full of lush greenery. Green is also associated with regeneration, fertility and rebirth for its connections to nature. Recent political groups in Europe and the West have taken on the color as a symbol of environmental protection and social justice, and consider themselves part of the Green movement, some naming themselves Green parties. This has led to similar campaigns in advertising, as companies have sold green, or environmentally friendly, products.

Etymology and linguistic definitions[link]

The etymology of the word "green" is related to nature and growth.

The application of terms to ranges of the visible spectrum are essentially arbitrary, cultural conventions. 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")

The word green comes from the Old English word grēne, earlier grœni. It is from a Common Germanic *gronja-, which is also reflected in Old Norse grænn, Old High German gruoni (but unattested in East Germanic), ultimately from a PIE root *ghre- "to grow", and root-cognate with grass and to grow.^[6] The first recorded use of the word as a color term in Old English dates to ca. AD 700.^[7]

Latin with viridis (and hence the Romance languages, and English vert, verdure etc.) also has a genuine term for "green". Likewise the Slavic languages with zelenъ. Ancient Greek also had a term for yellowish, pale green, χλωρός, cognate with χλοερός "verdant" and χλόη "the green of new growth".

Thus, the languages mentioned above (Germanic, Romance, Slavic, Greek) have old terms for "green" which are derived from words for fresh, sprouting vegetation. However, comparative linguistics makes clear that these terms were coined independently, over the past few millennia, and there is no identifiable single Proto-Indo-European or word for "green". For example, the Slavic zelenъ is cognate with Sanskrit hari "yellow, ochre, golden".^[8] The Turkic languages also have jašɨl "green" or "yellowish green", compared to a Mongolian word for "meadow".^[9]

Indeed, in the comparative study of color terms in the world's languages, green is only found as a separate category in languages with the fully developed range of six colors (white, red yellow, green, blue, black), identified as "Stage V" in Berlin and Kay (1969), or more rarely in systems with five colors (white, red yellow, green, black/blue). Many languages with a more reduced inventory of color terms have a single word for subsuming what would in English be called either blue or green, or more rarely black/blue/green or yellow/green/blue.^[10]

Thus, especially the distinction of green from blue is lacking in the traditional vocabulary of many languages.^[11] Modern languages have of course introduced supplementary vocabulary to denote "green", but these terms are recognizable as recent adoptions that are not in origin color terms (much like the English adjective orange being in origin not a color term but the name of a fruit). Thus, the Thai word เขียว besides meaning "green" also means "rank" and "smelly" and holds other unpleasant associations.^[12]

The Celtic languages had a term for "blue/green/grey", Proto-Celtic *glasto-, which gave rise to Old Irish glas "green, grey" and to Welsh glas "blue". This word is cognate with the Ancient Greek γλαυκός "bluish green", contrasting with χλωρός "yellowish green" discussed above.

In modern Japanese, the term for green is 緑, while the old term for "blue/green", blue (青, Ao^?) now means "blue". But in certain contexts, green is still conventionally referred to as 青, as in in blue traffic light (青信号, Ao shingō^?) and blue leaves (青葉, Aoba^?), reflecting the absence of blue-green distinction in old Japanese (more accurately, the traditional Japanese color terminology grouped some shades of green with blue, and others with yellow tones).

The Persian language is traditionally lacking a black/blue/green distinction. The Persian word سبز sabz can mean "green", "black" or "dark". Thus, Persian erotic poetry, dark-skinned women are addressed as sabz-eh, as in phrases like سبز گندم گون sabz-eh-gandom-gun (literally "dark wheat colored") or سبز مليح sabz-eh-malih ("a dark beauty").^[13] Similarly, in Sudanese Arabic, dark-skinned people are described as أخضر akhḍar, the term which in Standard Arabic stands unambiguously for "green".^[14]

In science[link]

Color vision and colorimetry[link]

Chlorophyll is responsible for the green color in plants.

The perception of greenness (in opposition to redness forming one of the opponent mechanisms in human color vision) is evoked by light which triggers the medium-wavelength M cone cells in the eye more than the long-wavelength L cones. Light which triggers this greenness response more than the yellowness or blueness of the other color opponent mechanism is called green. A green light source typically has a spectral power distribution dominated by energy with a wavelength of roughly 487–570 nm.^[15]

In additive color devices such as computer displays and televisions, one of the primary light sources is typically a narrow-spectrum yellowish-green of dominant wavelength ~550 nm; this "green" primary is combined with an orangish-red "red" primary and a purplish-blue "blue" primary to produce any color in between – the RGB color model. A unique green (green appearing neither yellowish nor bluish) is produced on such a device by mixing light from the green primary with some light from the blue primary.

By contrast in process color printing, a subtractive color system, green can be produced via a mixture of cyan and yellow ink, and in traditional color theory, green is produced by mixing yellow and blue paint.

Green is complementary to a purplish red or reddish purple color, in both additive and subtractive mixtures, and in simultaneous contrast effects and afterimages.

The sensitivity of the dark-adapted human eye is greatest at about 507 nm, a bluish-green color, while the light-adapted eye is most sensitive about 555 nm, a yellowish-green color.^[16] Human eyes have color receptors known as cone cells, of which there are three types. In some cases, one is missing or faulty, which can cause color blindness, including the common inability to distinguish red and yellow from green, known as deuteranopia or red–green color blindness.^[17] Green is restful to the eye. Studies show that a green environment can reduce fatigue.^[18]

In minerals and chemistry[link]

Emeralds come in many shades of green.

Many minerals provide pigments which have been used in green paints and dyes over the centuries. Pigments, in this case, are minerals which reflect the color green, rather that emitting it through luminescent or phosphorescent qualities. The large number of green pigments makes it impossible to mention them all. Among the more notable green minerals, however is the emerald, which is colored green by trace amounts of chromium and sometimes vanadium.^[19] Chromium(III) oxide (Cr₂O₃), is called chrome green, also called viridian or institutional green when used as a pigment.^[20] For many years, the source of amazonite's color was a mystery. Widely thought to have been due to copper because copper compounds often have blue and green colors, the blue-green color is likely to be derived from small quantities of lead and water in the feldspar.^[21] Copper is the source of the green color in malachite pigments, chemically known as basic copper(II) carbonate.^[22] Early painters would also use copper in the form of verdigris mixed with wax and turpentine to create green pigmentation in paints.^[23] Mixtures of oxidized cobalt and zinc were also used to create green paints as early as the 18th century.^[24] A more complete list of green minerals and pigments can be seen here.^[25][26]

Fireworks typically use barium salts to create green sparks.

There is no natural source for green food colorings which has been approved by the US Food and Drug Administration. Chlorophyll, the E numbers E140 and E141, is the most common green chemical found in nature, and only allowed in certain medicines and cosmetic materials.^[27] Quinoline Yellow (E104) is a commonly used coloring in the United Kingdom but is banned in Australia, Japan, Norway and the United States.^[28] Green S (E142) is prohibited in many countries, for it is known to cause hyperactivity, asthma, urticaria, and insomnia.^[29]

To create green sparks, fireworks use barium salts, such as barium chlorate, barium nitrate crystals, or barium chloride, also used for green fireplace logs.^[30] Copper salts typically burn blue, but cupric chloride (also known as "campfire blue") can also produce green flames.^[30] Green pyrotechnic flares can use a mix ratio 75:25 of boron and potassium nitrate.^[30] Smoke can be turned green by a mixture: solvent yellow 33, solvent green 3, lactose, magnesium carbonate plus sodium carbonate added to potassium chlorate.^[30]

In biology[link]

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

Green is common in nature, as many green plants use a complex chemical known as chlorophyll during photosynthesis.^[17] Chlorophyll does not absorb green light because it first arose in organisms living in oceans where purple halobacteria were already exploiting photosynthesis. Their purple color arose because they extracted energy in the green portion of the spectrum using bacteriorhodopsin. The new organisms that then later came to dominate the extraction of light were selected to exploit those portions of the spectrum not used by the halobacteria.^[31]

Animals typically use the color green as camouflage, blending in with the chlorophyll green of the surrounding environment.^[17] Green animals include, especially, amphibians, reptiles, and some fish, birds and insects. Most fish, reptiles, amphibians, and birds appear green because of a reflection of blue light coming through an over-layer of yellow pigment. Perception of color can also be affected by the surrounding environment. For example, broadleaf forests typically have a yellow-green light about them as the trees filter the light. Turacoverdin is one chemical which can cause a green hue in birds, especially.^[17] Invertebrates such as insects or mollusks often display green colors because of porphyrin pigments, sometimes caused by diet. This can causes their feces to look green as well. Other chemicals which generally contribute to greenness among organisms are flavins (lychochromes) and hemanovadin.^[17] Humans have imitated this by wearing green clothing as a camouflage in military and other fields. Substances that may impart a greenish hue to one's skin include biliverdin, the green pigment in bile, and ceruloplasmin, a protein that carries copper ions in chelation.

Lasers[link]

Lasers emitting in the green part of the spectrum are widely available to the general public in a wide range of output powers. Green laser pointers outputting at 532 nm (563.5 THz) are relatively inexpensive compared to other wavelengths of the same power, and are very popular due to their good beam quality and very high apparent brightness. The most common green lasers use diode pumped solid state (DPSS) technology to create the green light.^[32] An infrared laser diode at 808 nm is used to pump a crystal of neodymium-doped yttrium vanadium oxide (Nd:YVO4) or neodymium-doped yttrium aluminium garnet (Nd:YAG) and induces it to emit 281.76 THz (1064 nm). This deeper infrared light is then passed through another crystal containing potassium, titanium and phosphorus (KTP), whose non-linear properties generate light at a frequency that is twice that of the incident beam (563.5 THz); in this case corresponding to the wavelength of 532 nm ("green").^[33] Other green wavelengths are also available using DPSS technology ranging from 501 nm to 543 nm.^[34] Green wavelengths are also available from gas lasers, including the Helium-neon laser (543 nm), the Argon-ion laser (514 nm) and the Krypton-ion laser (521 nm and 531 nm), as well as liquid dye lasers. Green lasers have a wide variety of applications, including pointing, illumination, surgery, laser light shows, spectroscopy, interferometry, fluorescence, holography, machine vision, non-lethal weapons and bird control.^[35]

In culture[link]

In the 15th century "Saint Wolfgang and the Devil" by Michael Pacher, the Devil is green. Poets such as Chaucer also drew connections between the color green and the devil.^[36]

Nature[link]

In many folklores and literatures, green has traditionally been used to symbolize nature and its embodied attributes, namely those of life, fertility, and rebirth. Green was symbolic of resurrection and immortality in Ancient Egypt; the god Osiris was depicted as green-skinned.^[37] It is often used to describe foliage and the sea, and has become a symbol of environmentalism. Someone who works well with plants is said to have a green thumb or green fingers, and the word greenhorn refers to an inexperienced person.^[2] A company is said to be greenwashing if they advertise positive environmental practices to cover up environmental destruction.^[38][39] Green is used to describe anyone young, inexperienced, or gullible (probably by analogy to unripe, i.e. unready or immature, fruit).^[1] Green was the traditional color worn by hunters in the 19th century particularly the shade called hunter green. In the 20th century most hunters began wearing the color olive drab, a shade of green, instead of hunter green.^[40]

Love and lust[link]

Stories of the medieval period further portray it as representing love^[41] and the base, natural desires of man.^[42] In Persian and Sudanese poetry, dark-skinned women, called "green" women may be eroticized.^[14] The Chinese term for cuckold is "to wear a green hat."^[43] It is because in ancient China sex worker's husband wears Green Headscarf.^[44] Green is also used to describe jealousy and envy.^[1] In more modern times, the consumption of green M&M's has earned urban legendary status as a purported aphrodisiac.^[45]

Death, decay, and evil[link]

Green is also known to have signified witchcraft, devilry and evil for its association with faeries and spirits of early English folklore. It also had an association with decay and toxicity.^[46] Actor Bela Lugosi wore green-hued makeup for the role of Dracula in the 1927–28 Broadway stage production.^[47] A green tinge in the skin is sometimes associated with nausea and sickness.^[48] A physically ill person is said to look green around the gills.^[2] The color, when combined with gold, is seen as representing the fading of youth.^[49] In the Celtic tradition, green was avoided in clothing for its superstitious association with misfortune and death.^[50][51] Green is thought to be an unlucky color in British and British-derived cultures,^[52] where green cars, wedding dresses, and theater costumes are all the objects of superstition.^[53] Spider-Man villains were often colored green to represent a contrast to the hero's red.^[54] In some Far East cultures the color green is often used as a symbol of sickness and/or nausea.^[55]

Prosperity[link]

The United States one dollar note, like all other American dollar bills, is historically green.

In areas that use the U.S. Dollar as currency, green carries a connotation of money, wealth, and capitalism, because green is the color of United States banknotes, giving rise to the slang term greenback for cash.^[1] One of the more notable uses of this meaning is found in The Wonderful Wizard of Oz. In this story is the Emerald City, where everyone wears tinted glasses which make everything look green. According to the populist interpretation of the story, the city’s color is used by the author, L. Frank Baum, to illustrate the financial system of America in his day, as he lived in a time when America was debating the use of paper money versus gold.^[56] Green can communicate safety to proceed, as in traffic lights.^[2] In China, green is associated with the east, with sunrise, and with life and growth.^[57] In Thailand, the color green is consider auspicious for those born on a Wednesday day (light green for those born at night).^[58]

Nationality and politics[link]

Sovereign states with green flags:

  Islamic states using green

  Pan-African colors (red, black, and green)

  Other, most commonly to represent either lush national vegetation or heraldry

Several countries use green on their flags for symbolic or cultural reasons. Green, for example is one of the three colors (along with red and black, or red and gold) of Pan-Africanism. Several African countries thus use the color on their flags, including South Africa, Ghana, Senegal, Mali, Ethiopia, Togo, Guinea, Benin, and Zimbabwe. The Pan-African colors are borrowed from the Ethiopian flag, one of the oldest independent African countries. Green in these cases represents the natural richness of Africa.^[59]

Many flags of the Islamic world are green, as the color is considered sacred in Islam (see below). The flag of Hamas,^[60] as well as the flag of Iran, is green, symbolizing their Islamist ideology.^[61] The 1977 flag of Libya consists of a simple green field with no other characteristics. It was the only national flag in the world with just one color and no design, insignia, or other details.^[62] In the run-up to Iran's 2009 presidential election, the reformist candidate Mir-Hossein Mousavi chose green as his campaign color, and it became pervasive among his supporters during the campaign and the post-election protests.^[63] Green is the lowest of the three bands on the flag of India. The green stands for fertility and prosperity. Earlier Indian flags had contained a similar green band representing Islam, the second-most predominant religion in India.^[64]

Vert tincture

Other countries use flags for reasons of heraldry, or to represent lush national vegetation. In heraldry, green is called vert (French for "green"). Fourteenth century documents describe vert as a symbol of "jolliness and youth, but also of beauty and shame" as well as of death.^{[citation needed]} Vert is used for the flags of Wales and Hungary, and is the basis for the Brazilian flag as well — here as a tribute to Positivist movement which Auguste Comte had connected to the colour both as it stood for life and as it seemed to him powerful as the color of Islam.^[65][66] Other countries using green in their flags use it to represent their country's lush vegetation, as in the flag of Jamaica,^[67] and hope in the future, as in the flags of Portugal and Nigeria.^[68]

Wikisource has original text related to this article: The Wearing of the Green

Green is a symbol of Ireland, which is often referred to as the "Emerald Isle". The color is particularly identified with the republican and nationalist traditions in modern times. It is used this way on the flag of the Republic of Ireland, in balance with white and the Protestant orange.^[69] Green is a strong trend in the Irish holiday St. Patrick’s Day.^[70]

Green has become the symbolic color of environmentalism, chosen for its association with nature, health, and growth. The Green Party is any of various political parties emphasizing ecology, grassroots democracy, nonviolence, and social justice. Green Parties, now active in over one hundred countries, are more broadly included in the green movement, and most are members of the Global Green Network.^[71] The association of green with advocates of the environment has extended to other circles as well, as is the case with Patriarch Bartholomew I of Constantinople, who is often referred to as the "Green Patriarch" because the new environmental focus which he brought about within the Ecumenical Patriarchate.^[72]

Religion[link]

A green-colored strip in the modern flag of Libya.

Green is considered the traditional color of Islam. Muhammad is reliably quoted in a hadith as saying that "water, greenery, and a beautiful face" were three universally good things.^[73] In the Qur'an, sura Al-Insan, believers in God in Paradise wear fine green silk.^[3][74] Also, Al-Khidr ("The Green One"), is a Qur’anic figure who met and traveled with Moses.^[75]

Roman Catholic and more traditional Protestant clergy wear green vestments at liturgical celebrations during Ordinary Time.^[76] In the Eastern Catholic Church, green is the color of Pentecost.^[77] Green is one of the Christmas colors as well, possibly dating back to pre-Christian times, when evergreens were worshiped for their ability to maintain their color through the winter season. Romans used green holly and evergreen as decorations for their winter solstice celebration called Saturnalia, which eventually evolved into a Christmas celebration.^[78] In Ireland and Scotland especially, green is used to represent Catholics, while orange is used to represent Protestantism. This is shown on the national flag of Ireland.

Metaphysics[link]

In the metaphysics of the "New Age Prophetess", Alice Bailey, in her system called the Seven Rays which classifies humans into seven different metaphysical psychological types, the "third ray" of "creative intelligence" is represented by the color green. People who have this metaphysical psychological type are said to be "on the Green Ray".^[79] In Hinduism, Green is used to symbolically represent the fourth, heart chakra (Anahata).^[80] Psychics who claim to be able to observe the aura with their third eye report that someone with a green aura is typically someone who is in an occupation related to health, such as a physician or nurse, as well as people who are lovers of nature and the outdoors.^[81]

See also[link]

• List of colors
• Variations of green

Notes and references[link]

External links[link]

Find more about Green on Wikipedia's sister projects:
	Definitions and translations from Wiktionary
	Images and media from Commons
	Learning resources from Wikiversity
	News stories from Wikinews
	Quotations from Wikiquote
	Source texts from Wikisource
	Textbooks from Wikibooks

• Green All Over — slideshow by Life magazine