Cyan (// or //) is a greenish-blue or a light blue color. On the color wheels of the RGB (additive) and CMYK (subtractive) color models, it is located midway between blue and green, making it the complementary color of red.
Its name is derived from the Ancient Greek κύανος, transliterated kyanos, meaning "dark blue". It was formerly known as "cyan blue" or cyan-blue, and its first recorded use of as a color name in English was in 1879. Further origins of the color name can be traced back to a dye produced from the cornflower (Centaurea cyanus).
The web color cyan is synonymous with aqua. 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. Some varieties in the cyan color range are teal, turquoise, electric blue, aquamarine, and other colors described as blue-green.
In the subtractive color system, or CMYK color model, used in color printing, cyan is one of the primary colors, along with magenta, yellow, and black, which can be overlaid to produce all colors in the CMYK color model. In the additive color system, or RGB 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. Since it is the complement of red, it can also be made by the removal of red from white light. Mixing red light and cyan light at the right intensity on a black screen will make white. Cyan light has a wavelength of between 490 and 520 nanometers, between the wavelengths of blue and green.
Cyan on the web and in printing
The web colors cyan and aqua
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.
Process cyan (pigment cyan) (printer's cyan)
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. 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.
Cyan and cyanide
- Natural gas (methane), used by many for home cooking on gas stoves, has a cyan colored flame when burned with a mixture of air.
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.
- 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.
- Cyanosis is an abnormal blueness of the skin, usually a sign of poor oxygen intake. i.e. the patient is "cyanotic".
- Cyan is associated with the throat chakra in vedic medicine.
Why surgeons wear cyan 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 to patients.
In human culture
- Cyan colored tiles are often used to pave swimming pools to make the water within them seem more intensely colored, and therefore more inviting.
- Cyan was the name of the company that developed Myst and Riven.
- The ghost enemy Inky from the Game Pac-Man is cyan.
- In Star Wars Knights of the Old Republic II: The Sith Lords, players can have cyan-colored lightsabers. The color also appears in the previous game, but it was not called cyan due to the uniquely-named crystal that granted it.