Cyan

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Middle cyan,
sRGB # 00DDFF

color code: # 00DDFF
Cyan,
sRGB # 00FFFF

color code: # 00FFFF

Cyan (also found in the spelling cyan ) generally designates a hue at the transition from blue to green . The term is mainly used in technical and artistic applications and is very rare in everyday language. A generally accepted and definable color category cyan is missing here (in contrast to the orange at the transition from red to yellow ). In everyday language, the term turquoise is more common , but the hue so named, lying between blue and green, is not congruent with cyan in all shades.

term

The color name only has a more precise meaning in special applications, for example

  • as a colorimetrically defined color, in particular
  • as a base color in three color based subtractive color mixing ;
  • as a color category between blue and green within different color systems;
  • as a special shade of blue (i.e. a shade sub-range of blue), often also called cyan blue , for example to differentiate it from ultramarine blue ;
  • as a fashion color in the textile industry.

The meanings are explained in more detail in the article.

If you assign print cyan and web cyan to the same color tone wavelengths , you get the wavelength range from 482 nm to 492 nm. The information on a cyan assigned spectral range in some books varies and is only useful in the respective context, for example 487 nm to 492 nm with Norbert Welsch or 480 nm to 510 nm with Franz Wenzel.

Roof vaulted Frankfurt Airport station : color mixture blue to green

etymology

The word cyan goes back to ancient Greek κύανος , which denotes a deep, dark blue ( steel blue , black blue ).

As a more recent language development, the color term cyan has been introduced in German, especially through the Euroscale and fashionable design designs. In the RAL color system , which emerged in its beginnings in the middle of the 20th century, there is no cyan color category. However, color names are included in the composition with -turquoise. The turquoise colors are included in the green category.

Cyan as a colorimetrically defined color

The colors listed below are colorimetrically defined colors; their appearance is clearly defined by measured values ​​for certain lighting and viewing conditions.

Cyan as the basic color in four-color printing

Cyan is the name of the ISO 2846 and ISO 12647 standardized printing ink used in four-color printing . It is usually listed as print cyan or process cyan . The color appearance of the printed color is defined in normal daylight D50 . The pigment suitable for physical printing inks is the beta modification of copper phthalocyanine , which creates a greenish variant of phthalocyanine blue.

Color valence

According to ISO 2846-1, print cyan (0 ° / 45 ° geometry) has the following color values for a 2 ° CIE standard observer with a specified printing process:

lighting XYZ ( CIEXYZ color values ) L * a * b * ( CIELAB color values / D50)
Standard illuminant D50 (16.12, 24.91, 52.33) (56.99, -39.16, -45.99)
Standard illuminant D65 (18.74, 26.62, 68.54) (58.62, -30.63, -42.75)

The color is also possible to adapt to the viewing conditions outside the sRGB - gamut , so can not be displayed on a computer monitor in general. One can only try to approximate the appearance of the color on the screen as closely as possible.

Representation of the color in sRGB

Print cyan,
sRGB # 00B7EB

color code: # 00B7EB

Various visualizations of print cyan in sRGB (for example as a color sample on a white background) can be found, for example

Hexadecimal triplet HSV shade angle source
# 00B7EB H = 193 °
# 00ADEE H = 196 °
# 0D8BB1 H = 194 ° CIECAM02 (see below)

If the color model CIECAM02 is used , a gamut mapping to sRGB can be implemented through chroma reduction, which is optimally adapted to the perceived color tone. When using the LittleCMS software with the parameters

  • Source: (c.whitePoint = (85.30, 88.77, 67.90) (paper); c.surround = AVG_SURROUND; c.D_value = 1; c.La = 318; c.Yb = 20),
  • Target: (c.whitePoint = (95.04, 100.00, 108.90); c.surround = DIM_SURROUND; c.D_value = 0; c.La = 16; c.Yb = 20)

Iterative chroma reduction results in the sRGB color with hexadecimal triplet # 0D8BB1.

Spectral color of the same shade

There are various ways of assigning the colorimetrically defined color print cyan to a spectral color of the same color. The assignment in the color model CIECAM02 by increasing the chroma results in a wavelength of 482 nm. An assignment by subtracting white D50 within a physical color space results in a wavelength of 486 nm.

Cyan as a web color

Web color cyan,
sRGB # 00FFFF

color code: # 00FFFF

For the design of websites, there is a standardization of English color labels for defined web colors in HTML4 / CSS / SVG . The color names cyan and aqua both stand for the web color with sRGB hexadecimal triplet # 00FFFF, i.e. the additive mixture of blue and green within the sRGB color space, each with the maximum possible proportion. This corresponds to the HSV shade angle H = 180 °.

Particularly on the Internet, the standard color names have such a dominant position that many, even non-technical authors, with cyan , the web color cyan mine. In order to avoid misunderstandings, the terms web cyan or computer cyan should be preferred if the context is unclear. In English, Electric Cyan is used for this case .

Color valence

The direct conversion of the sRGB color values ​​using the formulas given in the sRGB specification results in the tristimulus values ​​of the color, which can be viewed as a relative color adapted to D65. A chromatic adaptation according to Bradford supplies these values ​​with adaptation to D50.

Adapted white XYZ ( CIEXYZ color values ) L * a * b * ( CIELAB color values / D50)
Standard illuminant D50 (52.81, 77.74, 81.11) (90.65, -50.63, -15.00)
Standard illuminant D65 (53.80, 78.73, 106.95) (91.11, -50.06, -33.41)

By using CIECAM02 (for comparison with the same parameters as above) the following tristimulus values ​​are obtained, which describe the theoretical appearance of web cyan as a printed color on white paper:

lighting XYZ ( CIEXYZ color values ) L * a * b * ( CIELAB color values / D50)
Standard illuminant D50 (45.93, 73.48, 77.13) (88.67, -60.70, -15.10)

Spectral color of the same shade

There are various ways of assigning the colorimetrically defined color web cyan a hue-like spectral color. The assignment in the color model CIECAM02 by increasing the chroma results in a wavelength of 490 nm. An assignment by subtracting white D65 within a physical color space results in a wavelength of 492 nm (491 nm in).

Cyan in color theory

When mixing colors

In an additive color space with the primary colors red, green, blue ( RGB color space ), cyan denotes the secondary color that arises from the additive mixture of green and blue.

In a subtractive color space with three basic colors and a large gamut, these primary colors usually have the names cyan, magenta and yellow ( CMY color model ).

As a complementary color

In various color theories , cyan is the complementary color to red.

Cyan as a color category and relative hue range

In many color classifications and color systems, cyan is used as a contrasting color name, often without a colorimetric definition of the color range. Which color tones cyan is supposed to include can only be roughly determined by comparing it with the surrounding color categories.

The following color classifications can be found (limited to blue and green tones):

  • Blue, cyan, green (both in the additive and subtractive color mixture with three basic colors as a list of all primary and secondary colors)
  • Blue, greenish blue, cyan, bluish green, green at Welsch there with actual indication of wavelength ranges of the same color.
  • Indigo, cyan (blue), green in Helmholtz's color theory
  • Violet blue, cyan blue, green with Harald Küppers
  • Violet blue, ultramarine blue, cyan blue, green in Newton's color theory
  • Ultramarine blue, cyan blue, blue green, yellow green reflected in the color selection of the 12-piece opaque paint box .

Related color names

averaged "turquoise",
sRGB # 39CBBC

color code: # 39cbbc
averaged "cyan",
sRGB # 3BBCD3

color code: # 3bbcd3

Related color names that do not restrict the brightness include turquoise, aquamarine, blue-green and green-blue.

The following picture of usage emerges:

  • When the name is used in a contrasting way, cyan in German usually means a more bluish shade than turquoise, aquamarine and blue-green
  • The term green-blue is rarely used.
Web color teal,
sRGB # 008080

Color code: # 008080
Cyan with white
component , sRGB # 80EEFF

color code: # 80EEFF

For light color variants and pastel colors from the cyan color range 482 nm to 492 nm, the color names light blue , sky blue and - especially in the textile sector - aqua can be found.

For dark color variants from the cyan color range 490 nm to 500 nm, the color names blue-green or sea-green are common, recently also the English names petrol (fashion range) and teal (web color). Teal is the standardized name for the web color, which is created from web cyan by reducing the brightness (sRGB hexadecimal triplet # 008080). In English, Teal also means teal , and the color name is probably derived from the color of the eyes of teal.

Classification as blue or green

Cyan is on the border between blue and green, with web cyan being greener than print cyan. Since cyan is not a commonly used color category, the corresponding colors are assigned to the color categories blue and green (possibly also turquoise) in everyday life.

Occurrence and use of color

In the nature

Cyan occurs naturally as the color of sky, water and ice due to certain refractions of light.

In everyday life

  • A middle cyan is often used as a pool color in swimming pools , the seen water color.
  • In fashion, a light medium cyan is popular for light women's tops ( aqua ).

Color psychology

In color psychology, cyan stands for clarity and intellectual openness, but also coolness and aloofness.

literature

  • Mark D. Fairchild: Color Appearance Models . Wiley & Sons, 2004. ISBN 0-470-01216-1 .
  • Mark D. Fairchild: [A Revision of CIECAM97s for Practical Applications. A Revision of CIECAM97s for Practical Applications .] In: Color Res Appl. Volume 26. (PDF file)
  • RWG Hunt: The Reproduction of Color . Wiley & Sons, 6th edition, 2004. ISBN 0-470-02425-9 .
  • Roy S. Berns: Billmeyer and Saltzman's Principles of Color Technology . Wiley & Sons, 3rd edition, 2000. ISBN 0-471-19459-X .
  • Dietmar Schuth: The color blue: attempting a characteristic . University of Heidelberg, dissertation, 1995. limited preview in the Google book search

Web links

  • Bruce Lindbloom website with many colorimetric conversion formulas and online calculators.

Individual evidence

  1. a b c d e f Norbert Welsch, Claus Chr. Liebmann: Colors. Nature - technology - art . 2nd Edition. Spektrum Akademischer Verlag, Munich 2004, ISBN 3-8274-1563-2 , p. 78
  2. ^ Franz Wenzel: AGFA light filter . fotokino-verlag, Halle 1957
  3. CSS Color Module Level 3. In: w3.org. May 14, 2003, accessed December 31, 2014 .
  4. a b The color spectrum in sRGB / The visible spectrum in sRGB. In: magnetkern.de. Accessed December 31, 2014 .
  5. Hermann von Helmholtz ( Memento from March 9, 2009 in the Internet Archive )
  6. Isaac Newton colorsystem.com, 2011 Context Research, Zurich.
  7. ^ Ernst Wilhelm von Brücke: The physiology of colors. Verlag von S. Hirzel, 1866, p. 18. Restricted preview in the Google book search
  8. a b c d Statistical analysis with free assignment of color names. In: colour.name. Accessed December 31, 2014 .