RYB color model RYB color model RYB (an abbreviation of red–yellow–blue) is a historical set of colors used in subtractive color mixing and is one commonly used set of primary colors. It is primarily used in art and design education, particularly painting. RYB predates modern scientific color theory, which has determined that cyan, magenta, and yellow are the best set of three colorants to combine, for the widest range of high-chroma colors. RYB (red–yellow–blue) make up the primary color triad in a standard artist's color wheel. The secondary colors purple–orange–green (sometimes called violet–orange–green) make up another triad. Triads are formed by three equidistant
Moving walkway the book, the fast lane stops while the second lane keeps running at ). In the Wells and Asimov works there are more steps in the speed scale and the speeds are less extreme. In Arthur C. Clarke's novel, "Against the Fall of Night" (later rewritten as "The City and the Stars") the Megacity of Diaspar is interwoven with "moving ways" which, unlike Heinlein's conveyor belts, are solid floors that can mysteriously move as a fluid. In the novel, Clarke writes, In his non-fiction book "Profiles of the Future", Arthur C. Clarke mentions moving sidewalks but made of some sort