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
Shades of red to this purity–power tradeoff and their "red" may be less colorful and more orangish than the standard red of sRGB. This color is also the color called "red" in the X11 web colors, which were originally formulated in 1987. It is also called "color wheel red". It is at precisely zero (360) degrees on the HSV color wheel, also known as the RGB color wheel (). Its complementary color is cyan. "Pigment red" is the color red that is achieved by mixing process (printer's) magenta and process (printer's) yellow in equal proportions. This is the color red that is shown