On Psychological Rainbows

Art for Non-Artists

One day in my middle school art class, everyone was handed a box of markers and the printout of a circle divided into six segments. We were told to color the segments carefully in order: red, orange, yellow, green, blue, purple. The rainbow we could linearly recite since kindergarten suddenly bent into an infinite loop. And so we learned the color wheel.

The color wheel neatly illustrates the concept of complementary colors — pairs of colors positioned on opposite sides of the circle. When wedged side by side, these pairs generate a strange and dramatic effect. They become brighter, almost swimming, bursting against sharp borders that are magnets for the gaze. Red and green, orange and blue, yellow and purple. I started to see pairs everywhere — advertisements, art, company logos, book covers. Pop art like Andy Warhol’s Madonna paintings began to make sense, with bold swathes of saturated color creating a tug-of-war for the eyes. Christmas decorations owe their allure to the striking combination of red and green. And in the natural world, the most spellbinding sunsets flaunt a vivid contrast between yellow and purple, orange and blue.

This remained an awesome revelation for several years, until I started learning about light in high school science class. The physics behind color radically upended my understanding of the color wheel: Visible light is merely a snippet of wavelengths within an immense continuum of electromagnetic radiation. So why on Earth are complementary colors special? It should not be possible, after all, to bend this subset of wavelengths into an infinite loop. From red to purple, the corresponding color wavelengths decrease smoothly. But it makes no sense that purple should be able to smoothly blend back into red, since at some point the wavelengths would have to jump from low to high. Thus, complementary colors, defined as opposites on the color wheel, seemed completely arbitrary.

Naturally, I reconciled this conflict by deciding that art and science were simply irreconcilable. It was an easy conclusion to reach. My science classes had never addressed anything artistic. And my art classes had never dealt with scientific concepts. I believed that, although I would always love art, my decision to pursue neuroscience made art separate and secondary to my true studies. Since the two disciplines never overlapped in my academic schedule, it seemed plausible that they were not meant to overlap at all. The science behind visible light didn’t have to explain the color wheel because science and art could exist in two disparate and contradictory worlds.


But years later, in a neuroscience lecture on color vision at Harvard, these two worlds came crashing back together. Although I’d deemed the visible light spectrum and the color wheel irreconcilable, I’d neglected the major link between them: the brain. After all, wavelengths of electromagnetic radiation are meaningless until the brain translates them into color. And it turns out the neurons responsible for this don’t merely identify wavelengths color by color. Instead, some get excited when they see one specific color (like red) and inhibited when they see another (like green), generating the illusion of pairs of opposite colors. And others get excited when one color (like red) dominates a center point, at the same time as its opposite color (like green) dominates the surrounding area. As a result, these respond most strongly to high contrast edges between two complementary colors.

Thus it’s the brain that turns science into art, and art back into science. A linear continuum of wavelengths of electromagnetic radiation gets fed into our minds, where it’s converted into a rainbow of colors, then psychologically bent into an infinite loop of opposites, which we learn to represent in middle school art class as the color wheel. Physics and neuroscience explain why art is so compelling: The cells in our brains are literally electrified by certain combinations of color. And art, in turn, gives significance to the blunt facts of biology: The arresting emotions that color can elicit are a testament to the power of these neural processes.

My science classes may have never addressed anything artistic, and my art classes may have never dealt with scientific concepts, but maybe they should have. Harvard has successfully created other spaces to study the intersection of the humanities, STEM, and social sciences, like History of Science, Global Health and Health Policy, and the digital humanities. But despite this push for interdisciplinarity at Harvard and in academia in general, it’s still so rare to find classes, much less concentrations, that combine (or even mention a combination of) art and science. For most non-artists, art is only available as a hobby, an elective, or a secondary field at best. It’s one of the greatest exceptions to the rule of interdisciplinarity, divided from science in the course catalog, relegated to our spare time. But this siloed mindset about art leads to countless missed opportunities, for art and science have never been two opposite worlds. Instead, they’re a continuum of concepts that blend into each other on loop. And our understanding of the world is deepened when we not only understand art and science in their own rights, but also understand how, when seen together, they create a more meaningful whole.

Isabella C. Aslarus ’21, a Crimson Design editor, lives in Leverett House. Her column appears on alternate Tuesdays.


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