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
Magenta colors of pigment. (The secondary colors of pigment are blue, green, and red.) As such, the hue magenta is the complement of green: magenta pigments absorb green light; thus magenta and green are opposite colors. The CMYK printing process was invented in the 1890s, when newspapers began to publish color comic strips. Process magenta 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 may be variations in the printed color that is pure magenta ink. A typical formulation of "process magenta" is shown in