The first color essay in the book is about red—but it’s also about color theory. This is a neat trick that Kastan and Farthing devised. Instead of writing about the color and its numerous, and often contradictory, cultural associations, they chose to give each chapter a specific line of inquiry. Red is about roses, but it’s also about language and thought and how color often seems to exist outside the world of dictionaries and thesauruses. “Color inevitably exceeds language—or maybe defeats it,” write Kastan and Farthing. They trace the evolution of color theory, from the Greeks’ understanding of color as something intrinsic to an object (though notably, Democritus, writing in the 5th century B.C.E., disagreed) to the Newtonian view. “Color, which once seemed so clearly to belong to the things we saw as colored, gradually was relocated: from the objects that ostensibly had them to the light by which we saw them, and, finally, to the mind, which lets us see that light as color,” Kastan explains. The way we perceive color is affected by so many factors, from the conditions of light to the hues that surround any given object. Color isn’t immutable and static. It “happens,” according to Kastan and Farthing. Roses aren’t simply red, and neither are sunsets or convertibles or apples. Of course, these things can all be red, but they can also appear brown or black or even blue, depending on the conditions.

Does this sound heavy? It’s not. The book never feels overly weighty or bogged down with jargon. The chapter on red also talks about the Internet sensation of “the dress,” the vision of pigeons, and the mechanics of optical illusions. There are digressions throughout, and humorous asides sprinkled in here and there. The book dances with its subject matter, dipping in and out of theory and analysis.

The chapters ebb and flow with a similar rhythm. Some are more rigorous than others, but none are lightweight. From the rosy-tinted look at color philosophy, Kastan and Farthing move into a discussion of orange and its late arrival into the English language. Unlike other hues, which are named for themselves and themselves alone, orange is named after an object. We call orange orange because of oranges. While the essay on red discussed a global perspective of color theory, this piece zeroes in on the history of the English language, from Chaucer to T.S. Eliot.

The next two entries, on yellow and green, move into cultural commentary. Yellow is about race, and how humanity has emphasized our physical differences through assigning inaccurate labels to entire groups of people. Although the primary focus is on Asian countries and the way that Western cultures have simultaneously stolen from them and degraded them, Kastan and Farthing do touch upon the greater issue of race:

Asians clearly but not inevitably became yellow, and similar stories could be told about how the indigenous population of North America became red, or Africans black, or even about how Caucasians came to be thought (or to think of themselves) white. The color coding of race now seems to us more or less natural—at least until we look. People are variously colored, but they are never colored with the color that putatively identifies them racially. We are all colored people; we just aren’t the colors people say we are.

It seems logical that, from questions of race, we would move into a discussion of politics. Green is the story of green parties and green movements, environmental awareness and independent politicians. But Kastan and Farthing don’t stop there. They also describe how other colors have come to be associated with specific political movements and nationalities. We learn about the colors of the Irish flag, and the Orange Revolution in Ukraine. We learn about the color of fascism (brown) and the history of America’s red state, blue state divide. Where one might expect to find a discussion of chlorophyll and chloroplasts, instead Kastan and Farthing choose to shine their light on revolutions and coups, patriots and rebels.

While it may seem excessive to have chapters on blue, indigo, and violet—all members of the same cool tribe—it works rather well. For Kastan and Farthing (and for many writers and artists who came before) blue is the color of transcendence. It’s also the color of depression, the heavens and the hell that we can experience on earth. Indigo is a story of a valuable dye. Indigo is emblematic of the ways in which humans have exploited other (differently pigmented) humans for color and profit. Violet, however, might just be my favorite chapter in the book. I’ve never been a fan of purple, but Kastan and Farthing have me reconsidering the color. Instead of focusing on purple and its connections to royalty, they decided to illuminate how violet was used by the impressionists to create a dreamy luminosity. For painters like Monet and Pissarro, violet was the color of the air, of twilight and shadows, of light itself. Pissarro’s Impressionist landscapes are revealed to be dually significant. They both gesture towards abstraction and attempt to capture the lived experience of looking strolling down a snowy lane. They ask the viewer to pay very close attention, but allow your eyes to go hazy, to both see and feel the world at once:

They offer a ravishing image and lure the viewer in toward them. But paying close attention disorganizes the world they seemingly present. Only by keeping your distance, one might say, does the world stay in focus. In most aspects of our life, it is the other way around: attentiveness is rewarded with clarity, and distance distorts and disfigures. But here we recognize the world only when we misrecognize the painting, or at least when we decide not to look carefully at it.

It’s genius, how these painters used violet. Even though I spent years studying art history, I had never considered the role purple played in the development of modern art. Kastan and Farthing pulled back the veil, allowing me to see this moody hue for what it is—radical, beautiful, bold.

As the book nears its end, it allows a move back toward the big-picture questions. It moves back towards more general inquiries in order to talk about the nonchromatic colors of black, white, and gray. This feels appropriate, considering the loaded nature of each hue. The essay on white is brilliant and searing, and the piece on black is a discussion of beginnings, endings, and nothingness. The story of gray is, surprisingly, also the story of migration. The chapter is ostensibly about photography, but at the end of the book, I found myself wondering about the morality of color. Color makes our lives more vivid, more beautiful. But it also hides ugly truths. Yet black and white photography (or “black to white,” as Kastan and Farthing more accurately call it) does no better a job of telling the truth.

This is the greatest triumph of the book. It reveals harsh truths about the world, while talking about a seemingly frivolous topic. It’s not overtly political, though one can easily deduce the authors’ leanings (they’re rather blue, if you haven’t guessed). But On Color is less concerned with politics than it is morality. It’s about seeing the world clearly, while retaining the ability to enjoy a good illusion.