Friday, 25 March 2011


Red is any of a number of similar colors evoked by light consisting predominantly of the longest wavelengths of light discernible by the human eye, in the wavelength range of roughly 630–740 nm.[2] Longer wavelengths than this are called infrared (below red), and cannot be seen by the naked eye. Red is used as one of the additive primary colors of light, complementary to cyan, in RGB color systems. Red is also one of the subtractive primary colors of RYB color space but not CMYK color space.

Etymology and definitions

The word red comes from the Old English rēad.[4] Further back, the word can be traced to the Proto-Germanic rauthaz and the Proto-Indo European root reudh-. In Sanskrit, the word rudhira means red or blood. In the English language, the word red is associated with the color of blood, certain flowers (e.g. roses), and ripe fruits (e.g. apples, cherries). Fire is also strongly connected, as is the sun and the sky at sunset. Healthy light-skinned people are sometimes said to have a "ruddy" complexion (as opposed to appearing pale). After the rise of socialism in the mid-19th century, red was used to describe revolutionary movements

In science

Colorimetry, color science, photography

Red is any of a number of similar colors evoked by light consisting predominantly of the longest wavelengths of light discernible by the human eye, in the wavelength range of approximately 630–700 nm.[2] Longer wavelengths than this are called infrared, or below red and cannot be seen by human eyes.[6] Red's wavelength has been an important factor in laser technologies as red lasers, used in early compact disc technologies, are being replaced by blue lasers, as red's longer wavelength causes the laser's recordings to take up more space on the disc than blue lasers.[7] A main theory for why primates developed sensitivity to red, is that it allowed ripe fruit to be distinguished from unripe fruit and inedible vegetation.[8] This further drove other adaptations to take advantage of this new ability, such as red faces.[9] Red light is also used to preserve night vision in low-light or night-time situations, as the rod cells in the human eye aren't sensitive to red.[10][11] Red is one of the three additive primary colors of light, complementary to cyan, in RGB color systems. Red is also one of the three subtractive primary colors of RYB color space but not CMYK color space.[12]

One common use of red as an additive primary color is in the RGB color model. Because red is not by itself standardized, color mixtures based on red are not exact specifications of color either. The United States government sets certain specifications for what paints to use when red is stated in a design.[13] In order for computers to produce exact colors, the color red needs to be defined in terms of an absolute color space, such as sRGB.[14] color correction (so that a standardized red is produced that is not in fact full intensity of only the red colorant).

Red illumination was (and sometimes still is) used as a safelight while working in a darkroom, as it does not expose most photographic paper and some films.[15] Though many more modern darkrooms use an amber safelight, red illumination is closely associated with the darkroom in the public mind.[16]
 In nature
Mars possesses a distinct red color, particularly when seen up close

Mars is called the Red Planet because of the reddish color imparted to its surface by the abundant iron oxide present there.[17] Astronomical objects which are moving away from the observer exhibit a red shift. Jupiter's surface displays a Great Red Spot, a football-shaped gigantic storm south of the planet's equator.[18] Many elements exhibit a red color when burned; calcium, for example, produces a brick-red when combusted.[19]
Red blood cell agar

Oxygenated blood is red due to the presence of oxygenated hemoglobin.[20] When used about animal coloration red usually refers to a brownish, reddish-brown or ginger color. In this sense it is used to describe coat colors of reddish-brown cattle and dogs, and in the names of various animal species or breeds such as red fox, red squirrel, red deer, Robin Redbreast, Red Grouse, Red Knot, Redstart, Redwing, Red Setter, Red Devon cattle etc. The usage for animal color appears similar to that for red ochre, red hair and Red Indian. When used for flowers, red often refers to purplish (red deadnettle, red clover, red helleborine) or pink (red campion, red valerian) colors.

Red is associated dominance in a number of animal species.[21] For example, in mandrills red coloration of the face is greatest in alpha males, increasingly less prominent in lower ranking subordinates, and directly correlated with levels of testosterone.[22] Red can also affect the perception of dominance by others, leading to significant differences in mortality, reproductive success and parental investment between individuals displaying red and those not.[23] In humans, wearing red has been linked with increased performance in competitions, including professional sport[24][25] and multiplayer video games.[26] Controlled tests have demonstrated that wearing red does not increase performance or levels of testosterone during exercise, so the effect is likely to be produced by perceived rather than actual performance.[27] Judges of tae kwon do have been shown to favor competitors wearing red protective gear over blue,[28] and, when asked, a significant majority of people say that red abstract shapes are more "dominant", "aggressive" and "likely to win a physical competition" than blue.[21] In contrast to its positive effect in physical competition and dominance behavior, exposure to red decreases performance in cognitive tasks[29] and elicits aversion in psychological tests where subjects are placed in an "achievement" context (e.g. taking an IQ test)


Red is used as a symbol of guilt, sin and anger, often as connected with blood or sex.[31] A Biblical example is found in Isaiah: "Though your sins be as scarlet, they shall be white as snow."[32] Also, The Scarlet Letter, an 1850 American novel by Nathaniel Hawthorne, features a woman in a Puritan New England community who is punished for adultery with ostracism, her sin represented by a red letter 'A' sewn into her clothes.[33] This all comes from a general Hebrew view inherited by Christianity which associates red with the blood of murder,[34] as well as with guilt in general. Often, things will be in red to scare.[35] Another popular example of this is in the phrase "caught red-handed", meaning either caught in an act of crime or caught with the blood of murder still on one's hands.[36] At one point, red was associated with prostitutes, or now, with brothels (red-light districts).[37][38] In Roman Catholicism, red represents wrath, one of the Seven Deadly Sins. In Christianity, Satan is usually depicted as colored red and/or wearing a red costume in both iconography and popular culture.[39] Statistics have shown that red cars are more likely to be involved in accidents.[40]

The color red is associated with lust, passion, love, and beauty as well. The association with love and beauty is possibly related to the use of red roses as a love symbol.[41] Both the Greeks and the Hebrews considered red a symbol of love, as well as sacrifice.[42] Psychological research has shown that men find women who are wearing red more attractive


Red catches people's attention, and can be used either in a negative way to indicate danger and emergency, or in a positive way in advertising to gain more viewers, or in nature, as a ripe fruit announces its readiness with its red color.[48] Several studies have indicated that red carries the strongest reaction of all the colors, with the level of reaction decreasing gradually with orange, yellow, and white, respectively.[49] Because of this, red is often used to catch people's attention in a variety of situations (see: penalty card).[50]

The port, or left, side of a sea-going vessel carries a red navigation light, to warn other vessels approaching from that side to change course to avoid a collision.

Eastern and African traditions

In China, red (simplified Chinese: 红; traditional Chinese: 紅; pinyin: hóng) is the symbol of fire and the south (both south in general and Southern China specifically). It carries a largely positive connotation, being associated with courage, loyalty, honor, success, fortune, fertility, happiness, passion, and summer.[52][53] In Chinese cultural traditions, red is associated with weddings (where brides traditionally wear red dresses) and red paper is also frequently used to wrap gifts of money or other things. Special red packets (simplified Chinese: 红包; traditional Chinese: 紅包; pinyin: hóng bāo) in Mandarin or lai see in Cantonese are specifically used during the Chinese New Year to give monetary gifts. On the more negative side, obituaries are traditionally written in red ink, and to write someone's name in red signals either cutting them out of your life, or that they have died.[53] Red is also associated with both the feminine and the masculine (yin and yang respectively), depending on the source.[53][54]

In Japan, red is a traditional color for a heroic figure.[55] In the Indian Sub-continent, red is the traditional color of bridal dresses, and is frequently represented in the media as a symbolic color for married women. The color is associated with purity, sexuality in marriage relationships through its connection to heat and fertility.[56] It is also the color of wealth, beauty, and the goddess Lakshmi.[44]

In Central Africa, Ndembu warriors rub themselves with red during celebrations. Since their culture sees the color as a symbol of life and health, sick people are also painted with it. Like most Central African cultures, the Ndembu see red as ambivalent, better than black, but not as good as white.[57] In other parts of Africa, however, red is a color of mourning, representing death.[58] Because of the connection red bears with death in many parts of Africa, the Red Cross has changed its colors to green and white in parts of the continent

In sports

Teams throughout the world wear red on their uniforms. Major League Baseball is especially well known for red teams. Numerous teams in various sports use red in their team colors.[60]

The Cincinnati Red Stockings are the oldest professional baseball team, dating back to 1869.[61] The franchise soon relocated to Boston and is now the Atlanta Braves, but its name survives as the origin for both the Cincinnati Reds and Boston Red Sox. During the 1950s when red was so strongly associated with communism, the modern Cincinnati team was known as the "Redlegs" and the term was even used on baseball cards. After the red scare faded, the team was known as the Reds again.[62]

In the NHL, red jerseys are worn by the Detroit Red Wings, Washington Capitals, Atlanta Thrashers, Calgary Flames, Carolina Hurricanes, Chicago Blackhawks, Colorado Avalanche, Minnesota Wild, Montreal Canadiens, Ottawa Senators, Phoenix Coyotes, and the New Jersey Devils.

In association football, teams that wear red as part of their kit include Manchester United, Liverpool FC, Arsenal FC, AFC Ajax, Bayern Munich and AC Milan. In rugby union, New Zealand's Canterbury provincial team and Crusaders Super 14 rugby side wear red as a major color in their playing strips.

The Cleveland Cavaliers basketball team use a deeper shade of red called wine. A similar shade (known in this instance as claret) is used by English association football teams Aston Villa FC, West Ham United FC, and Burnley FC.

Numerous national teams wear red, often through association with their national flags. These national sides include representative teams in various sports from Spain, England, Wales, Canada, Denmark, Tonga, Chile, and Switzerland.