Shades of blue pigment blue, is the tone of blue that is achieved by mixing process (printer's) cyan and process (printer's) magenta in equal proportions. It is displayed at right. The purpose of the CMYK color system is to provide the maximum possible gamut of color reproducible in printing by the use of only three primaries. The color indicated is only approximate as the colors of printing inks may vary. The color defined as "blue" in the NCS or Natural Color System is an azure-like color shown at right (NCS 2060-B). The Natural Color System is a color system based on the four
RG color space replicated accurately in the RG color space. There is a similar color space called RGK which also has a black channel. Outside of a few low-cost high-volume applications, such as packaging and labelling, RG and RGK are no longer in use because devices providing larger gamuts such as RGB and CMYK are in widespread use. Until recently, its primary use was in low-cost light-emitting diode displays, where red and green tended to be far more common than the still nascent blue LED technology, though full-color LEDs with blue have become more common in recent years. ColorCode 3-D, a stereoscopic color