Blue is one of the three primary colours in the RYB colour model (traditional colour theory), as well as in the RGB (additive) colour model . [2] It lies between violet and cyan on the spectrum of visible light . The term blue generally describes colors perceived by humans observing light with a dominant wavelength between approximately 450 and 495 nanometres . Most blues contain a slight mixture of other colours; azure contains some green, while ultramarine contains some violet. The clear daytime sky and t
Blue has been an important colour in art and decoration since ancient times. The semi-precious stone lapis lazuli was used in ancient Egypt for jewellery and ornament and later, in the Renaissance , to make the pigment ultramarine , the most expensive of all pigments. [3] In the eighth century Chinese artists used cobalt blue to colour fine blue and white porcelain . In the Middle Ages , European artists used it in the windows of cathedrals . Europeans wore clothing coloured with the vegetable dye woad unti
In the United States and Europe, blue is the colour that both men and women are most likely to choose as their favourite, with at least one recent survey showing the same across several other countries, including China, Malaysia, and Indonesia. [5] [6] Past surveys in the US and Europe have found that blue is the colour most commonly associated with harmony, confidence, masculinity, knowledge, intelligence, calm, distance, infinity, the imagination, cold, and sadness. [7]