How do humans see color?

You're probably reading this on a computer screen that appears to display a variety of colors. But in fact, nothing in or on that screen has blue, yellow or magenta color—anymore than radio waves have color. Indeed, the light waves traveling from the screen to your eye are the same kind of energy as the radio waves that may be connecting your computer to a wireless router—just energy.

Color doesn't reside in computer screens, apples and oranges, or shiny new cars. It exists in your mind, where your brain interprets a limited palette of information from a tiny region of the electromagnetic spectrum as color.

What then happens at the eye's retina, and in the brain's visual cortex that allows us to see several million discrete colors? On these pages, as in much of science, you'll find only a few concrete answers, but you may find some really interesting new questions.

Three of the greatest physicists of the nineteenth century postulated answers to such questions. These giants of classical color theory were James Clerk Maxwell, Thomas Young, and Hermann von Helmholtz.

In the 1950s, Edwin Land, inventor of the Polaroid camera, discovered some fascinating properties of color vision that raise questions Maxwell, Young, and Helmholtz never imagined

© J. C. Adamson, 1997, 2012

A Starting Point

Your first grade teacher didn't lie to you about primary colors. But she only knew a bit of the truth.

Some of the History

Young's lucky guess led us to the science of color reproduction. Did it also lead us to a century and a half of misunderstanding?

Did Maxwell know he couldn't photograph red and green? Why should we care?

Can Land's discoveries explain Maxwell's demonstration?

The Playground

The Sandbox—a place to experiment with color mixture. Just for fun, or to develop a color scheme.

A fascinating demonstration of color vision fatigue, and of complementary colors.

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