Tertiary color if they exist at all, though indigo and scarlet are standard for blue–violet and red–vermilion. In another sense, a tertiary color is obtained by mixing secondary-colored pigments. These three colors are russet (orange–purple), slate (purple–green), and citron (green–orange), with the corresponding three quaternary colors plum (russet–slate), sage (slate–citron), buff (citron–russet) (with olive sometimes used for either slate or citron). Beyond that are shades of grey (blue grey and brown greys), which approach but never quite reach black. The RYB color terminology outlined above and in the color samples shown below is ultimately derived from the 1835 book "Chromatography", an analysis
British racing green (such as the Triumph Spitfire, Austin-Healey Sprite, MG MGB and the Lotus Elan), Mazda produced a limited edition version of the model in 1991 and 2001 called the "British Racing Edition", which included green paint. Similarly, the modern BMW-owned Mini Hatchback marque, which is assembled at their Oxford, Birmingham and Swindon factories, includes a BRG colour option. Originally a somewhat murky dark olive, this was updated to a fresher shade of metallic green in the 2011 version. Imperial Chemical Industries, Belco Car Finishes, Colour Mixing Book 1953, as used on Jowett Cars 1948-1953 British racing green British racing green, or