Indigo is the
color on the
electromagnetic spectrum between about 450 and 420
nm in
wavelength, placing it between
blue and
violet. Color scientists do not usually recognize indigo as a significant color category, and generally classify wavelengths shorter than about 450 nm as violet.
[1]
Indigo and violet are different from
purple, which cannot be seen on the electromagnetic spectrum but can be achieved by mixing
blue light with
red light.
One can see spectral indigo by looking at the reflection of a fluorescent tube in a non-recordable
compact disc. This works because the CD functions as a
diffraction grating, and a
fluorescent lamp generally has a peak at 435.833 nm (from
mercury), as is visible on the fluorescent lamp spectrum.
Distinction between four shades of indigo
Like many other colors (
orange and
violet are the best-known), indigo gets its name from an object in the natural world—the plant named
indigo once used for dyeing cloth (see also
Indigo dye).
The color
electric indigo is an approximation of
spectrum indigo. This is the brightest color indigo that can be approximated on a computer screen—it is the color between the
web color blue and the color electric
violet.
The web color
blue violet or
deep indigo is a shade of indigo brighter than pigment indigo but not as bright as electric indigo.
The color
pigment indigo is equivalent to the
web color indigo and approximates the color indigo that is usually reproduced in pigments and colored pencils.
The color of
indigo dye is a different color than either spectrum indigo or pigment indigo. This is the actual color of the dye from the indigo plant when swatched onto raw fabric. A vat full of this dye is a darker color, approximating the web color
Midnight Blue.
When specifying the color
indigo, it is necessary to indicate which particular one of these four major shades of indigo you are referring to.
Electric indigo
| Electric Indigo
|
| <imagemap>Image:Information-silk.png|About these coordinates
rect 0 0 50 50 About these coordinates
desc none</imagemap>— Color coordinates — |
| Hex triplet | #6600FF |
| RGBB | (r, g, b) | (102, 0, 255) |
| HSV | (h, s, v) | (264°, 100%, 100%) |
| Source | HTML Color Chart @264 |
B: Normalized to [0–255] (byte)
|
In an RGB
color space, spectral indigo and violet must be approximated by purples, that is, by mixing a little red with a lot of blue. Spectral indigo is closely approximated by the color
electric indigo. This sample was taken directly from the
CIE chromaticity diagram opposite the 430 nanometer line. It is much brighter than the pigment indigo reproduced below. Spectrum Indigo fits nicely between spectrum
violet and spectrum
blue as can be seen in the color bands displayed below. It is impossible to represent spectrum indigo exactly on a computer screen, because true spectrum indigo is outside the color triangle or
gamut of the RGB
color space defined by the monitor primaries.
Indigo is neither an additive
primary color nor a subtractive primary color. It was named and defined by
Isaac Newton when he divided up the
optical spectrum (which is a continuum of frequencies). He specifically named
seven colors primarily to match the seven notes of a western
major scale, because he believed sound and light were physically similar, but also to link colors with the (known)
planets,
days of the
week, and other lists that had seven items.
Humans do not tend to recognize indigo as a separate
hue category between blue and violet. For this reason, some commentators, including
Isaac Asimov, have suggested that indigo should not be regarded as a color in its own right but merely as a shade of blue or violet. Color scientists typically divide the spectrum at about 450 nm between violet and blue, with no indigo.
[1][2]
Others continue to accept it
[3] as it has been accepted traditionally as one of
Newton's named colors of the
spectrum along with
red,
orange,
yellow,
green,
blue, and
violet.
Deep indigo (web color blue violet)
| Blue Violet
|
| <imagemap>Image:Information-silk.png|About these coordinates
rect 0 0 50 50 About these coordinates
desc none</imagemap>— Color coordinates — |
| Hex triplet | #8A2BE2 |
| RGBB | (r, g, b) | (138, 43, 226) |
| HSV | (h, s, v) | (271°, 81%, 89 %) |
| Source | X11 |
B: Normalized to [0–255] (byte)
|
At right is displayed the
web color blue violet, a color intermediate in brightness between electric indigo and pigment indigo. This color is also called
deep indigo.
Pigment indigo (web color indigo)
| Pigment Indigo
|
| <imagemap>Image:Information-silk.png|About these coordinates
rect 0 0 50 50 About these coordinates
desc none</imagemap>— Color coordinates — |
| Hex triplet | #4B0082 |
| RGBB | (r, g, b) | (75, 0, 130) |
| HSV | (h, s, v) | (275°, 60%, 51%) |
| Source | X11 |
B: Normalized to [0–255] (byte)
|
The color box at right displays the
web color Indigo which is equivalent to
pigment indigo, the color indigo as it would be reproduced by artists' paints as opposed to the brighter indigo above (electric indigo) that it is possible to reproduce on a computer screen.
Pigment indigo can be obtained by mixing 55% pigment
cyan with about 45% pigment
magenta.
Compare the subtractive colors to the additive colors in the two primary color charts in the article on
primary colors to see the distinction between electric colors as reproducible from light on a computer screen (additive colors) and the pigment colors reproducible with pigments (subtractive colors); the additive colors are a lot brighter because they are produced from light instead of pigment.
Pigment indigo (web color indigo) represents the way the color indigo was always reproduced in pigments, paints, or colored
pencils in the
1950s.
By the
1970s, because of the advent of
psychedelic art, artists became used to brighter pigments, and pigments called "bright indigo" or "bright blue-violet" that are the pigment equivalent of the electric indigo reproduced in the section above became available in artists' pigments and colored pencils.
Indigo dye
| Indigo Dye
|
| <imagemap>Image:Information-silk.png|About these coordinates
rect 0 0 50 50 About these coordinates
desc none</imagemap>— Color coordinates — |
| Hex triplet | #00416A |
| RGBB | (r, g, b) | (0, 65, 106) |
| HSV | (h, s, v) | (275°, 40%, 40%) |
| Source | ISCC-NBS |
B: Normalized to [0–255] (byte)
|
At right is displayed the color
indigo dye, an approximation of the color of a swatch of
indigo dye.
Sample of Indigo Dye color:
ISCC-NBS Dictionary of Color Names (1955)--Color Sample of Indigo Dye (Indigo color sample #179)
Indigo in human culture
Food
- The outer skin of many varieties of eggplant is colored pigment indigo.
- So called "purple" carrots and potatoes are actually colored pigment indigo.
Midwifery
- In the ancient Maya civilization indigo was the one color that was recognized for its soothing effect on pregnant women and their unborn children. Pregnant women often wore this color in order to protect themselves and their child from danger and to ensure a safe and successful delivery.
New Age Philosophy
- The color electric indigo is used to symbolically represent the sixth chakra (called Ajna), which is said to include the third eye. This chakra is believed to be related to intuition and gnosis (spiritual knowledge). [4]
Parapsychology
Sociology
Video Games
- The color most associated with the Nintendo Gamecube is a purplish indigo, officially deemed indigo.
See also
References
1.
^ J. W. G. Hunt (1980). Measuring Color. Ellis Horwood Ltd. ISBN 0-7458-0125-0.
2.
^ Craig F. Bohren and Eugene E. Clothiaux (2006). Fundamentals of Atmospheric Radiation. Wiley-VCH. ISBN 3527405038.
3.
^ Tansley, David V.
Subtle Body: Essence and Shadow New York: 1984 Avon (Art and Cosmos series--Jill Purce, Editor) It is pointed out that
New Age artists and
philosophers accept indigo as a spectrum color because it is used to represent one of the seven
chakras (the sixth) of the
subtle body.
4.
^ Graham, Lanier F. (editor)
The Rainbow Book Berkeley, California:1976 Shambala Publishing and The Fine Arts Museums of San Francisco (Handbook for the Summer 1976 exhibition
The Rainbow Art Show which took place primarily at the
De Young Museum but also at other museums)
Indigo Pages 152-153 The color indigo is stated to represent intuition.
5.
^ Oslie, Pamalie
Life Colors: What the Colors in Your Aura Reveal Novato, California:2000--New World Library Indigo Auras: Pages 161-174
6.
^ Varichon, Anne
Colors:What They Mean and How to Make Them New York:2006 Abrams Page 171
Indigo is a color between blue and violet.
Indigo may also mean:
- Plants and animals
- Indigofera, the Indigo plant
- Indigo Bunting, a small North-American bird
- Indigo Snake, the genus Drymarchon
..... Click the link for more information. Color or colour[1] (see spelling differences) is the visual perceptual property corresponding in humans to the categories called red, yellow, blue, black, etc.
..... Click the link for more information.
electromagnetic (EM) spectrum is the range of all possible electromagnetic radiation. The "electromagnetic spectrum" (usually just spectrum) of an object is the frequency range of electromagnetic radiation with wavelengths from thousands of kilometers down to fractions of
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1 nanometre =
SI units
010−9 m 010−3 μm
US customary / Imperial units
010−9 ft 010−9 in
A
nanometre (American spelling:
nanometer, symbol
nm..... Click the link for more information. In physics, wavelength is the distance between repeating units of a propagating wave of a given frequency. It is commonly designated by the Greek letter lambda (λ). Examples of wave-like phenonomena are light, water waves, and sound waves.
..... Click the link for more information.
The term blue may refer to any of a number of similar colours. The sensation of blue is made by light having a spectrum dominated by energy in the wavelength range of about 440–490 nm.
..... Click the link for more information.
As the name of a color, violet (named after the flower violet) is used in two senses: first, referring to the color of light at the short-wavelength end of the visible spectrum, approximately 380–420 nm when indigo is recognized, or more commonly 380–450 nm[1]
..... Click the link for more information.
Purple in colloquial English usage is any shade of color occurring between blue and red; this color is sometimes confused with the more narrowly-defined spectral color violet.
In color theory a Purple is defined as any non-spectral color between violet and red.
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The term blue may refer to any of a number of similar colours. The sensation of blue is made by light having a spectrum dominated by energy in the wavelength range of about 440–490 nm.
..... Click the link for more information.
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 625–750 nm.
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Compact Disc
The closely spaced tracks on the readable surface of a Compact Disc cause light to diffract into a full visible colour spectrum
Media type: Optical disc
Encoding: Various
Capacity: Typically up to 700 MB
..... Click the link for more information.
diffraction grating is an optical component with a surface covered by a regular pattern of parallel lines, typically with a distance between the lines comparable to the wavelength of light.
..... Click the link for more information.
fluorescent lamp is a gas-discharge lamp that uses electricity to excite mercury vapor in argon or neon gas, resulting in a plasma that produces short-wave ultraviolet light. This light then causes a phosphor to fluoresce, producing visible light.
..... Click the link for more information.
2, 1
(mildly basic oxide)
Electronegativity 2.00 (scale Pauling)
Ionization energies 1st: 1007.1 kJ/mol
2nd: 1810 kJ/mol
3rd: 3300 kJ/mol
Atomic radius 150 pm
Atomic radius (calc.
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orange occurs between red and yellow in the visible spectrum at a wavelength of about 585 – 620 nm, and has a hue of 30° in HSV colour space. The complementary colour of orange is azure, a slightly greenish blue.
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As the name of a color, violet (named after the flower violet) is used in two senses: first, referring to the color of light at the short-wavelength end of the visible spectrum, approximately 380–420 nm when indigo is recognized, or more commonly 380–450 nm[1]
..... Click the link for more information.
Indigofera
Species
See text
Indigofera is a large genus of about 700 species of flowering plants belonging to the family Fabaceae.
..... Click the link for more information.
Indigo dye is dye with a distinctive blue color (see indigo). The chemical compound that constitutes the indigo dye is called indigotin. The ancients extracted the natural dye from several species of plant as well as one of the two famous Phoenician sea snails, but nearly all
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Web colors are colors used in designing web pages, and the methods for describing and specifying those colors.
Authors of web pages have a variety of options available for specifying colors for elements of web documents.
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The term blue may refer to any of a number of similar colours. The sensation of blue is made by light having a spectrum dominated by energy in the wavelength range of about 440–490 nm.
..... Click the link for more information.
As the name of a color, violet (named after the flower violet) is used in two senses: first, referring to the color of light at the short-wavelength end of the visible spectrum, approximately 380–420 nm when indigo is recognized, or more commonly 380–450 nm[1]
..... Click the link for more information.
Web colors are colors used in designing web pages, and the methods for describing and specifying those colors.
Authors of web pages have a variety of options available for specifying colors for elements of web documents.
..... Click the link for more information.
Midnight blue is a dark shade of blue, close to black, that was named for its darkness. Midnight blue is the color of a vat full of Indigo dye; therefore, midnight blue may also be considered a dark shade of indigo.
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RGB color model is an additive model in which red, green, and blue (often used in additive light models) are combined in various ways to reproduce other colors. The name of the model and the abbreviation ‘RGB’ come from the three primary colors, red, green, and blue and
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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 625–750 nm.
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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 nm. It is considered one of the additive primary colors.
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The term blue may refer to any of a number of similar colours. The sensation of blue is made by light having a spectrum dominated by energy in the wavelength range of about 440–490 nm.
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HSL and HSV (also called HSB) are two related representations of points in an RGB color space, which attempt to describe perceptual color relationships more accurately than RGB, while remaining computationally simple.
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Hue is one of the three main attributes of perceived color, in addition to lightness and chroma (or colorfulness). Hue is also one of the three dimensions in some colorspaces along with saturation, and brightness (also known as lightness or value).
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colorfulness, chroma, and saturation are related concepts referring to the intensity of a specific color. More technically, colorfulness is the perceived difference between the color of some stimulus and gray, chroma
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