In the 1660s, English physicist and mathematician Isaac Newton began a series of experiments with sunlight and prisms. He demonstrated that clear white light was composed of seven visible colors.

By scientifically establishing our visible spectrum (the colors we see in a rainbow), Newton laid the path for others to experiment with color scientifically. His work led to breakthroughs in optics, physics, chemistry, perception, and the study of color in nature.

Aristotle developed the first known theory of color, believing God sent it from heaven through celestial rays of light. He suggested that all colors came from white and black (lightness and darkness) and related them to the four elements – water, air, earth, and fire. Aristotle’s beliefs on color were widely held for over 2000 years until being replaced by those of Newton.

Opticks, one of the greatest works in the history of science, documents Newton’s discoveries from his experiments, passing light through a prism. He identified the ROYGBIV colors (red, orange, yellow, green, blue, indigo, and violet) that make up the visible spectrum. The visible spectrum is the narrow portion within the electromagnetic spectrum that can be seen by the human eye. Other forms of electromagnetic radiation, waves of energy that we cannot see include radio, gamma, and microwaves. The cells in our eyes called cones are sensitive to wavelengths found in the visible spectrum. They allow us to see all the colors of the rainbow.