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),
Secondary color Secondary color A secondary color is a color made by mixing of two primary colors in a given color space. For the human eye, good primary colors of light are red, green, and blue. Combining lights of these colors produces a large range of visible colors. That is, the primary and secondary RGB colors (with secondary colors in boldface) are: Combining RGB colors means adding light (thus the term "additive color"), and the combinations are brighter. When all three primaries are combined in equal amounts, the result is white. The RGB secondary colors produced by the addition of light turn