Shades listed under the American Federal Standard form their own group because they are identified by number rather than by name. The five-digit code states the sheen in its first digit and the specific tone in the rest, so a colour can be taken straight from a monograph or a painting diagram with nothing left to interpretation. Builders of US aircraft and modern equipment meet these codes constantly, which is why the shades are kept together. Because a painting diagram for a modern US type usually cites nothing but FS numbers, a whole scheme can be bought in one pass and sprayed without interpreting anything: the airframes are in aircraft model kits, and the equipment for laying an even coat across a large wing in airbrushes and compressors.
