RAL colour standard relates to the shade of the colour: This collection, which follows the naming of RAL Classic, was invented in 1961. It is nowadays made up of ten colours (RAL 1039-F9 Sand beige, RAL 1040-F9 Clay beige, RAL 6031-F9 Bronze green, RAL 6040-F9-Light olive, RAL 7050-F9 Camouflage grey, RAL 8027-F9 Leather brown, RAL 8031-F9 Sand brown, RAL 9021-F9 Tar black and RAL 6031-HR Bronze green for non-camouflage applications), used by the "Bundeswehr" for military camouflage coating. In 1993 a new colour matching system was introduced, tailored to the needs of architects, designers and advertisers. It started with 1,688 colours and was
The Missing Shade of Blue he later says, "this instance is so singular, that it is scarcely worth our observing" he cannot be referring to this particular example, but rather to the "type" of exception that it represents. It is also said that when Hume says, "Let all the different shades of that colour, except that single one, be placed before him, descending gradually from the deepest to the lightest; it is plain that he will perceive a blank, where that shade is wanting", he is assuming that colours are composed of a set of distinct independent hues, when in reality they form a continuum.