Color theory defining the CMY primaries as substances that "absorbed" only one of the retinal primary colors: cyan absorbs only red (−R+G+B), magenta only green (+R−G+B), and yellow only blue violet (+R+G−B). It is important to add that the CMYK, or process, color printing is meant as an economical way of producing a wide range of colors for printing, but is deficient in reproducing certain colors, notably orange and slightly deficient in reproducing purples. A wider range of color can be obtained with the addition of other colors to the printing process, such as in Pantone's Hexachrome printing ink system (six colors),
Shades of blue system are the three colors of light chosen such as to provide the maximum gamut of colors that are capable of being represented on a computer or television set. This color is also called color wheel blue. It is at precisely 240 degrees on the HSV color wheel, also known as the . It is a spectral color which lies at, or near, the short-wave (violet) end of the traditional "blue" and possibly was classified as "indigo" by Newton. Its complementary color is yellow. The color defined as "blue" in the CMYK color system used in printing, also known as