Throughout history, the perception that color resulted from combining light and darkness persisted among theorists and scientists until the 17th century. Following numerous experiments by various physicists and researchers to project sunlight onto an object using a prism, which generated colors, the first approximations of how light works are attributed to Isaac Newton, who proposed the first theories of color that remain valid in our modern society to this day.
The popular experiment of projecting light onto a prism, resulting in a rainbow, which has been carried out both intentionally and by chance, was the experiment that gave Newton the key to formulating his own theory that would contribute to understanding the phenomenon of colors.
Public domain photograph via cosmos.so/public-work
In 1665, the physicist, theologian, and inventor Isaac Newton (1642–1726) conducted the well-known and renowned practical experiment of double refraction of light: in a darkened room, a beam of natural light was projected onto a white object. This beam of light was intercepted by a prism, resulting in the seven colors that make up the rainbow: yellow, red, orange, violet, green, blue, and cyan. This 17th-century experiment was the first demonstration that white light is actually the product of a process of color mixing. To test this hypothesis, which held that the prism was not the object that projected the colors, but rather that the colors were intrinsic to the light itself, Newton carried out two complementary experiments:
In the first experiment, he added another prism on the opposite side of the first prism to reverse the experiment. The result was that the second prism again combined all the colors, generating white light.
The second of these was Newton's disc: a disc with the seven colors mentioned before, which, when rotated rapidly on an axis, gives rise to the perception of the color white.
Sir Isaac Newton. Stipple engraving by J. Scott after Sir G. Kneller, 1702. Original public domain image from Wellcome Collection. Via rawpixel.com
Within that extensive practical research on light and optics, for which his name is not so well recognized, but rather for other theories such as the law of gravitation/gravity, or the theoretical foundations of mechanics, Newton laid the foundations of the theory of colors still valid today: bodies absorb all colors, except the perceived one, which is the one reflected in the human eye.
All his theories of color, as well as his research on refraction, reflection and perception of light, were compiled in his work "Opticks" published in 1704.
Newton, Isaac. Opticks, or a Treatise of the Reflections, Refractions, Inflections and Colors of Light, 1704. {{PD-US-expired}}
In his studies, Isaac Newton did not attempt to link colors to variables associated with perception beyond optics. The first studies related to relevant physical and chemical aspects are attributed to the German chemist Wilhelm Ostwald (1853-1932).
