On Vision and Colors tried to demonstrate physiologically that color is "specially modified activity of the retina." The initial basis for Schopenhauer's color theory comes from Goethe's chapter on physiological colors, which discusses three principal pairs of contrasting colors: red/green, orange/blue, and yellow/violet. This is in contrast to the customary emphasis on Newton's seven colors of the Newtonian spectrum. In accordance with Aristotle, Schopenhauer considered that colors arise by the mixture of shadowy, cloudy darkness with light. With white and black at each extreme of the scale, colors are arranged in a series according to the mathematical ratio between the proportions of light and
Full-spectrum light from lights not marketed as "full-spectrum". Color temperature and Color Rendering Index (CRI) are the standards for measuring light. There is no technical definition of "full-spectrum" so it cannot be measured. To compare "full-spectrum" sources requires direct comparison of spectral distribution. The emission spectrum of a light source varies depending on the light generating mechanism. Thermal sources such as incandescent bulbs produce electromagnetic radiation over a broad and continuous range of wavelengths, including infrared and ultraviolet. A black body radiator is the idealized version of a thermal source. As the temperature of a black body radiator increases, the shape of