Colour is the visual perceptual property corresponding in humans to the categories called red, orange, yellow, green, blue, violet…. Colour derives from the spectrum of light (distribution of light intensity versus wavelength) interacting in the eye with the spectral sensitivities of the light receptors. Colour categories and physical specifications of colour are also associated with flowers, objects, materials (pigments, dyes, stones, wood, metals and alloys…), light sources, etc., based on their physical properties such as light absorption, reflection, or emission spectra.
Colours Wavelength intervals (nm) Infrared 1000 ; 700 Red 700 ; 630 Orange 630 ; 570 Yellow 570 ; 550 Green 550 ; 500 Blue 500 ; 450 Violet 450 ; 400 Ultraviolet 400 ; 100
color, Farbe (Deut.), color (Esp.), couleur (Fr.), colore (It.), cor, tinta (Port.)