Color model or "CMYK" color space. The cyan ink absorbs red light but transmits green and blue, the magenta ink absorbs green light but transmits red and blue, and the yellow ink absorbs blue light but transmits red and green. The white substrate reflects the transmitted light back to the viewer. Because in practice the CMY inks suitable for printing also reflect a little bit of color, making a deep and neutral black impossible, the K (black ink) component, usually printed last, is needed to compensate for their deficiencies. Use of a separate black ink is also economically driven when a lot
Blue–green distinction in language Blue–green distinction in language Many languages do not distinguish between what in English are described as "blue" and "green" and instead use a cover term spanning both. To describe this English lexical gap, linguists use the portmanteau word "grue", from "green" and "blue", which the philosopher Nelson Goodman coined in his 1955 "Fact, Fiction, and Forecast" to illustrate the "new riddle of induction". The exact definition of "blue" and "green" may be complicated by the speakers not primarily distinguishing the hue, but using terms that describe other color components such as saturation and luminosity, or other properties of the object