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 its spectral distribution changes with more energy emitted at shorter (bluer) wavelengths. Sources that rely on fluorescence have a different emission spectrum shape than do thermal sources. Some wavelengths will be produced with greater amplitude than others. Fluorescent sources used for lighting, such as fluorescent lamps, white light emitting diodes, and metal halide lamps are intended to produce light at all wavelengths, but the distribution is different from thermal sources and so colors will appear different under these forms of lighting than under daylight; some colors may match under one light source that don't appear the same under another, a