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),
Blue–green distinction in language "siwy" means blue-gray in Polish (literally it means the color of gray hair). The word "siny" refers to violet-blue and is used to describe the color of bruises ("siniaki"), hematoma, and the blue skin discoloration that can result from moderate hypothermia. Russian does not have a single word referring to the whole range of colors denoted by the English term "blue". Instead, it traditionally treats light blue (голубой, "goluboy") as a separate color independent from plain or dark blue (синий, "siniy"), with all seven "basic" colors of the spectrum (red–orange–yellow–green–голубой / "goluboy" (sky blue, light azure, but "does not equal"