Cyan
Spectral coordinates
Wavelength	490-520 nm
Frequency	610-575 THz
Common connotations
water[1][2][3]
Color coordinates
Hex triplet	#00FFFF
sRGBB  (r, g, b)	(0, 255, 255)
Source	CSS Color Module Level 3
B: Normalized to [0-255] (byte) H: Normalized to [0-100] (hundred)

Cyan (^[4] or rarely, ^[5]) is a greenish-blue color.^[6][7] It is evoked by light with a predominant wavelength of between 490-520 nm, between the wavelengths of green and blue.^[8]

In the subtractive color system, or CMYK (subtractive), which can be overlaid to produce all colors in paint and color printing, cyan is one of the primary colors, along with magenta, yellow, and black. In the additive color system, or RGB (additive) color model, used to create all the colors on a computer or television display, cyan is made by mixing equal amounts of green and blue light. Cyan is the complement of red; it can be made by the removal of red from white light. Mixing red light and cyan light at the right intensity will make white light.

The web color cyan is synonymous with aqua. Other colors in the cyan color range are teal, turquoise, electric blue, aquamarine, and others described as blue-green.

Gallery

• 

  In the RGB color model, used to make colors on computer and TV displays, cyan is created by the combination of green and blue light.

• 

  In the RGB color wheel of additive colors, cyan is midway between blue and green.

• 

  In the CMYK color model, used in color printing, cyan, magenta and yellow combined make black. In practice, since the inks are not perfect, some black ink is added.

• 

  Color printers today use magenta, cyan, and yellow ink to produce the full range of colors.

• 

  Cyan and red are complementary colors. They have strong contrast and harmony, and if combined, they make either white, black or grey, depending upon the color system used.

• 

  Cyan is the color of shallow water over a sandy beach. The water absorbs the color red from the sunlight, leaving a greenish-blue color.

• 

  The dome of the Tilla Kari Mosque in Samarkand, Uzbekistan (1660) is cyan. The color is widely used in architecture in Turkey and Central Asia.

• 

  The planet Uranus. seen from the Voyager 2 spacecraft. The cyan color comes from clouds of methane gas in the planet's atmosphere.

• 

  A surgical team in Germany. Surgeons and nurses often wear gowns colored cyan, and operating rooms are often painted that color, because it is the complement of red and thus reduces the emotional response to blood red that occurs when doing surgery on internal organs.^[9]

Etymology

Its name is derived from the Ancient Greek , transliterated kyanos, meaning "dark blue, dark blue enamel, lapis lazuli".^[10][11] It was formerly known as "cyan blue"^[12] or cyan-blue,^[13] and its first recorded use as a color name in English was in 1879.^[14] Further origins of the color name can be traced back to a dye produced from the cornflower (Centaurea cyanus).^[15][16]

In most languages, 'cyan' is not a basic color term and it phenomenologically appears as a greenish vibrant hue of blue to most English speakers. Reasons for why cyan is not linguistically acknowledged as a basic color term can be found in the frequent lack of distinction between blue and green in many languages.

Cyan on the web and in printing

The web colors cyan and aqua

Cyan (additive secondary)
Color coordinates
Hex triplet	#00FFFF
sRGBB  (r, g, b)	(0, 255, 255)
Source	X11
B: Normalized to [0-255] (byte) H: Normalized to [0-100] (hundred)

The web color cyan shown at right is a secondary color in the RGB color model, which uses combinations of red, green and blue light to create all the colors on computer and television displays. In X11 colors, this color is called both cyan and aqua. In the HTML color list, this same color is called aqua.

The web colors are more vivid than the cyan used in the CMYK color system, and the web colors cannot be accurately reproduced on a printed page. To reproduce the web color cyan in inks, it is necessary to add some white ink to the printer's cyan below, so when it is reproduced in printing, it is not a primary subtractive color. It is called aqua (a name in use since 1598) because it is a color commonly associated with water, such as the appearance of the water at a tropical beach.^[17]

Process cyan (pigment cyan) (printer's cyan)

Cyan (subtractive primary)
Color coordinates
Hex triplet	#00B7EB
sRGBB  (r, g, b)	(0, 183, 235)
Source	CMYK[19]
B: Normalized to [0-255] (byte) H: Normalized to [0-100] (hundred)

Cyan is also one of the common inks used in four-color printing, along with magenta, yellow, and black; this set of colors is referred to as CMYK as in spectrum(s).

While both the additive secondary and the subtractive primary are called cyan, they can be substantially different from one another. Cyan printing ink can be more saturated or less saturated than the RGB secondary cyan, depending on what RGB color space and ink are considered.

Process cyan is not an RGB color, and there is no fixed conversion from CMYK primaries to RGB. Different formulations are used for printer's ink, so there can be variations in the printed color that is pure cyan ink. This is because real-world subtractive (unlike additive) color mixing does not consistently produce the same result when mixing apparently identical colors, since the specific frequencies filtered out to produce that color affect how it interacts with other colors. Phthalocyanine blue is one such commonly used pigment. A typical formulation of process cyan is shown in the color box at right.

In science and nature

Color of water

• Pure water is nearly colorless. However, it does absorb slightly more red light than blue, giving large volumes of water a bluish tint; increased scattering of blue light due to fine particles in the water shifts the blue color toward green, for a typically cyan net color.^[20]

Cyan and cyanide

• Cyanide derives its name from Prussian blue, a blue pigment containing the cyanide ion.^[21]

Bacteria

• Cyanobacteria (sometimes called blue-green algae) are an important link in the food chain.^[22]

Astronomy

• The planet Uranus is colored cyan because of the abundance of methane in its atmosphere. Methane absorbs red light and reflects the blue-green light which allows observers to see it as cyan.^[23]

Energy

• Natural gas (methane), used by many for home cooking on gas stoves, has a cyan colored flame when burned with a mixture of air.^[24]

Photography and film

• Cyanotype, or blueprint, a monochrome photographic printing process that predates the use of the word cyan as a color, yields a deep cyan-blue colored print based on the Prussian blue pigment.^[25]
• Cinecolor, a bi-pack color process, the photographer would load a standard camera with two films, one orthochromatic, dyed red, and a panchromatic strip behind it. Color light would expose the cyan record on the ortho stock, which also acted as a filter, exposing only red light to the panchromatic film stock.^[26][27]

Medicine

• Cyanosis is an abnormal blueness of the skin, usually a sign of poor oxygen intake. i.e. the patient is "cyanotic".^[28]
• Cyan is associated with the throat chakra in vedic medicine.^[29]

Surgeons' gowns

• In the 19th century, surgeons wore white gowns, but in the 20th century surgeons began to wear cyan or green surgical gowns, for several reasons. First, in the brightly lit operating room, cyan reflected less light than white and caused less strain on the eyes of the medical team. Second, cyan is the complementary color of red, so red blood on a cyan gown looks black or gray rather than red, and is not as vivid. Also, shifting your sight to cyan after staring at red for long periods of time does not cause cyan after-images, as shifting from red to white will do. Lastly, since cyan is considered a restful and soothing color, it causes less anxiety in patients.^[30]

See also

• Blue-green distinction in language
• Shades of cyan
• List of colors
• Orange (colour), formerly called "yellow-red" (compare with blue-green)

References