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The Wonderful Color Wheel: Part 3

Welcome, color fans, to part 3 of the history of the color wheel. (Catch up with part 1 and part 2 here.)

Readers sent me a flood of lesser-known (and gorgeous) color wheels I hadn’t covered, so we’re going to hop around in time to squeeze all that color-candy in. We’ll also answer your pressing questions, like: what are the “true” primary colors? Why can’t you mix paints to produce white? And why isn’t brown in the rainbow?

Back in the mid-1800s, nicely — if artificially — symmetrical color stars burst briefly into vogue. Above is George Field’s 1841 color wheel from his book Chromatography, or, A treatise on colours and pigments: and of their powers in painting. Other fans of the star shape include Auguste Laugel’s color star from L’Optique et les Arts (1869) and Charles Blanc in Grammaire des arts du dessin (1867).

Two strands run through this phase of the color wheel’s history. First, the scientists start to separate from artists, each thinking color through for their own purposes. (That said, scientists still lobbed in many useful tidbits that artists, designers and pigment manufacturers made full creative use of.)

Second, color theorists started differentiating between how color mixing works when you’re talking about mixing light (additive mixing) versus mixing pigments (subtractive mixing). Understanding the differences had big implications for printing, photography, TV and the full-color Internet you’re gazing at now.

In the camp of folks puzzling out the creative and psychological sides of color was Charles Hayter, who first posited the idea of “warm” and “cool” colors in his 1813 book Perspective (pictured above).

In 1824, chemist Michel-Eugène Chevreul took the helm of the fabled Gobelin Dyeworks of Paris. His mission: to brighten up the apparently dullness of dyes the factory produced. Chevreul offered a surprising take on the issue: the dullness wasn’t a matter of bad dyes, but rather caused by complementary colors weaved closely together. When viewed from a distance, these colors tended to blend into an optical grayness.

Chevreul later expounded on this theory in two landmark books, De la loi du contraste simultané des couleurs (On the Law of Simultaneous Contrast of Colors), 1839, and Des couleurs et leurs applications aux arts industriels (On Colors and Their Application in the Industrial Arts), 1864.

If Newton got his facts straight, why can’t you make white by mixing all the colors in your paintbox? The answer lies in additive versus subtractive mixing. Additive mixing of colored light tends toward lightness, while mixing pigments subtractively tends to dull the resulting color.

This concept also neatly explains why there are several sets of primary colors: red, blue, and yellow for paints and pigments; cyan-magenta-yellow-black for processing printing; and red-green-blue for colored light. Read on!

The king of additive mixing was arguably Scottish physicist and mathematician James Clerk Maxwell. Maxwell strode like a monster among 19th-century scientists, responsible for discovering electromagnetics, the kinetic theory of gases, and laying the groundwork for quantum physics and mechanics.

Not only did he explain additive versus subtractive mixing in color, he also figured out that color photos and film could be successfully formed using red-green-blue (RGB) light filters, proving it by making the world’s first color photo this way.

Maxwell’s RGB light mixing still dominates the hexadecimal color coding system used on web monitors, televisions, and countless tiny, glowing screens today. Under RGB, each color gets a six-digit code representing how much red, green and blue respectively should be additively mixed to render it accurately in lights.

On the subtractive side of things, Ogden Rood, author of Modern Chromatics (1879), was useful to painters interested in controlling the effects of subtractive mixing on their canvases.

CMYK printing also counts as subtractive mixing, by printing a color image in successive layers of cyan, magenta, yellow and black / grayscale. (CMYK identified points in between the traditional color-divisions of the rainbow: cyan contains both blue and green, magenta both red and purple, et cetera.) Shockingly, CMYK technology broke through first in 1722, invented by French-German painter Jacob Christoph Le Blon. Although Le Blon’s process was too finicky to be practical in large-scale production, nor were the printing dyes of the day equal to the task, the man pioneered a truly big idea in color printing.

Blasting headlong into the 20th century, we’ve already discussed Munsell’s color system, invented in 1900. The chief heir to Munsell is the CIE chromaticity curve, named for the French Commission Internationale de l’Éclairage. On the tongue-shaped CIE curve, Newton’s “pure” spectral colors lie along the outer edges, mixing to white at the center.

The CIE color space accounts for hue (color itself) and saturation (a color’s purity, or how much black or white has been mixed in). It doesn’t account for color’s intensity or brightness. For that, you’d need a stack of CIE diagrams, which would reveal the startling fact that brown is, actually, a low-intensity yellow or orange.

… all of which lands us squarely in the here and now, where color wheels exert a peculiar charm: bracingly energetic, but also calming and complete.

What’s your favorite modern-day take on the color wheel as a visual icon?