Cyan

Cyan (from Greek κυανός, meaning "blue") may be used as the name of any of a number of a range of colors in the blue/green part of the spectrum. In reference to the visible spectrum cyan is used to refer to the color obtained by mixing equal amounts of green and blue light or the removal of red from white light. As such, cyan is the complement of red in RGB and CMYK color systems: cyan pigments absorb red light.

Cyan is also called aqua or blue-green, and was previously known as "cyan blue".

Some shades of color close to cyan in the cyan color range are baby blue, turquoise and aquamarine.

Electric cyan (web color aqua)
The vivid cyan that is seen on an electronic display device (shown at right) is also referred to as electric cyan to distinguish it from the less vivid turquoise-like process cyan used in CMYK color printing (shown below). (Note: while the color is defined by definite RGB values, the display of the color will vary depending on the absolute color space used and the nature of the physical display device, e.g. computer monitor, and if this page is printed it is likely that the color shown will be far from representative.)

The web color aqua is an alias for electric cyan, i.e., it is exactly the same color.

To reproduce electric 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)
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.

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. A typical formulation of process cyan is shown in the color box at right. The source of the color shown at right is the color cyan that is shown in the diagram located at the bottom of the following website offering tintbooks for CMYK printing:. 

Light Sea Green
At right is displayed the web color light sea green.

Dark Cyan
At right is displayed the web color dark cyan.

Cyan in nature

 * Pure water is colorless, but due to scattering can appear to be blue or cyan.
 * Cyanobacteria (sometimes called blue-green algae) are an important link in the food chain.
 * Cyanide derives its name from Prussian blue, a blue pigment containing the cyanide ion.

Architecture

 * Cyan colored tiles are often used to pave swimming pools to make the water within them seem more inviting to swim in, by making the cyan color of their water seem more intensely colored. Water in swimming pool is colored a bright tint of cyan anyway because chlorine bleach, which is cyan, is added to water in swimming pools for disinfection.

Astronomy

 * The planet Uranus is cyan.

Business

 * The logo of the Pacific Gas and Electric Company is a dark cyan color.

Computer Games/Video Games

 * There is a computer game company called Cyan Worlds (a.k.a., Cyan, Inc.).
 * There is a Final Fantasy VI character named Cyan Garamonde.

Interior Design and Industrial Design

 * The color cyan (called aqua by interior designers) was commonly used in the interior design of the 1950s in combination with either magenta or pink and black to give a modern feel to interiors (These colors were also popular for automobiles in the 1950s.).

Medical

 * Cyanosis is an abnormal blueness of the skin, usually a sign of poor oxygen intake.

Music

 * There is a band called Cyan, a British progressive rock band from the 1980s and 1990s.

Panelology

 * Cyan is the name of a character in the Norwegian comic strip Nemi.

Photography

 * 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.

Religion

 * In Catholic Christianity cyan represents the deadly sin Sloth.