Orange (colour) Orange (colour) Orange is the colour between yellow and red on the spectrum of visible light. Human eyes perceive orange when observing light with a dominant wavelength between roughly 585 and 620 nanometres. In painting and traditional colour theory, it is a secondary colour of pigments, created by mixing yellow and red. It is named after the fruit of the same name. The orange colour of carrots, pumpkins, sweet potatoes, oranges, and many other fruits and vegetables comes from carotenes, a type of photosynthetic pigment. These pigments convert the light energy that the plants absorb from the sun into chemical
George Palmer (colour theorist) is moved by its own ray." This statement has proved true in regard to the number of different light sensor types, the cones, in the human eye, if not in regard to the claim of three kinds of light. Twenty-five years later a similar statement was made by the eminent physicist Thomas Young. Voigt, in his report on Giros von Gentilly, describes him as having stated that colour blindness arises if one or two of the three kinds of "particles" (light sensors) in the retina are inactive, a statement found to be accurate. In 1786 Palmer provided a hypothesis for