The Science of Color

Newton’s Rainbow

Sir Isaac Newton experimenting with a prism. Engraving after a picture by J.A. Houston, ca. 1870. Courtesy of The Granger Collection, New York

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 in a scientific manner. 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 it was sent by God 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.

Sir Isaac Newton
Opticks, or, A treatise of the reflections, refractions, inflections and colours of light...
London, 1704

Opticks, one of the great 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 the wavelengths found in the visible spectrum. They allow us to see the all the colors of the rainbow.

…if the Sun’s Light consisted of but one sort of Rays, there would be but one Colour in the whole World…

–Sir Isaac Newton, Opticks

Johann Wolfgang von Goethe
Zur Farbenlehre [Theory of Colors]
Tübingen: J.G. Cotta'schen Buchhandlung, 1810

Goethe challenged Newton’s views on color, arguing that color was not simply a scientific measurement, but a subjective experience perceived differently by each viewer. His contribution was the first systematic study on the physiological effects of color. Goethe’s views were widely adopted by artists. Although Goethe is best known for his poetry and prose, he considered Theory of Colors his most important work.

Colour are light’s suffering and joy.

–Johann Wolfgang von Goethe

This very rare book formed the foundation for modern color printing. Le Blon was the first to outline a three-color printing method using primary colors (red, yellow, blue) to create secondary colors (green, purple, orange). He makes an important distinction between “material colors,” as used by painters, and colored light, which was the focus of Newton’s color theories. Le Blon’s distinction marks the first documentation of what is now referred to as additive and subtractive color systems. Rainbows, TVs, computer screens and mobile devices all emit light and are examples of an additive color system (the subject of Newton’s Opticks). Red, green and blue are the primary additive colors and when combined they produce transparent white light. Books, paintings, grass and cars are examples of a subtractive color system which is based on the chemical makeup of an object and its reflection of light as a color. Subtractive primary colors - blue, red, and yellow – are often taught to us as children, and when mixed together they create black.

…I arriv’d at the skill of reducing the Harmony of Colouring in painting to Mechanical Practice…

–J.C. Le Blon, Coloritto

Brown leather cover of a book adorned with gold embossed lines and stars. There is a rainbow spectrum bar diagonally across the cover. Above the spectrum is a gold embossed sun, below is a line schematic of a sphere. A fold out page of a book showing twelve spectrum bars. The first three bars are a full spectrum with some black lines appearing. The remainder are mostly black with colored lines appearing on various places on the spectrum indicating chemical make-up.
Henry E. Roscoe
Spectrum Analysis: Six Lectures . . .
London: Macmillan, 1869

These colorful line diagrams reveal the chemical compositions of metals. When a pure metal is burned and viewed through a spectroscope, each element gives off unique spectra, a sort of color fingerprint. This method, called spectral analysis, led to the discovery of new elements, and marked the first steps towards quantum theory.

A circle made up of varying sizes of dots. The dots are colored such that a number appears to those without color blindness and the number is invisible for those with color blindness. A circle made up of varying sizes of dots. The dots are colored such that a number appears to those without color blindness and the number is invisible for those with color blindness. A circle made up of varying sizes of dots. The dots are colored such that a number appears to those without color blindness and the number is invisible for those with color blindness.
Shinobu Ishihara
The Series of Plates Designated as Tests for Colour-Blindness
Tokyo: Kanchara & Co., 1936

Can you see the numbers in the circles? 4.5 percent of the population cannot see the entire visible spectrum, a condition called color vision deficiency, or color blindness. Ishihara plates are used to test patients for the various types of color blindness.

Gerald Handerson Thayer
Illustrstions by Abbott Handerson Thayer (his father)
Concealing-Coloration in the Animal Kingdom
New York: The Macmillan Co., 1909

Can you find the animal hiding in this image? Camouflage uses color to conceal forms by creating optical illusions. American artist Abbott Thayer introduced the concept of disruptive patterning, in which an animal’s uneven markings can disguise its outline. In this illustration Thayer shows how a peacock can disappear into its surroundings.

Thayer, an American artist, devoted much of his life to understanding how animals conceal themselves in nature for survival. In his book, Concealing Coloration in the Animal Kingdom, Thayer presented his beliefs of protective coloration as an essential factor in evolution helping animals disguise themselves from predators. He received much praise and criticism. He was extreme in his views arguing that all animal coloration was for protective purposes and failing to recognize other possible reasons such as sexual selection – characteristics for attracting a mate.  Teddy Roosevelt most notably attacked his theories by pointing out that this concealment doesn’t last all season, or even all day, but was dependent on a single frozen moment in times. Despite these shortcomings, Thayer went on to be the first to propose camouflage for military purposes.  Although his suggestions were initially rejected, his former students were among the founders of the American Camouflage Society in 1916 and his theories were eventually adopted and are still used today.

Albatross D.Va, 1917-1918
Courtesy of the National Air and
Space Museum

The colorful pattern on this German aircraft from World War I is called lozenge camouflage. Its disruptive pattern applied Abbott Thayer’s theories in an effort to inhibit enemy observation from the air and on the ground.