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 out to be good primary colors for pigments, the mixing of which subtracts light. Pigments, such as inks and paint, display color by absorbing some wavelengths of light and reflecting the remainder. When pigments are combined, they absorb the combination of their colors, and reflect less. Thus, combining pigments results in a darker color. This is called subtractive color-mixing, as mixing pigments subtracts wavelengths from the light that is reflected. The mixture of equal amounts of these colors produce the secondary colors red, blue, and "lime" green (the RGB primary colors of light), as follows: That is, the primary and