Evolution of the Color Blue

Dov Michaeli
Dov Michaeli, MD, PhD, author of The Doctor Weighs In (on Everythng)

Have you noticed in ancient literature that the sea and sky were described as anything but the color blue? Were people back then color blind or…

A friend of mine turned my attention to an interview with Guy Deutscher, an Israeli linguist who published the book “Through the Language Mirror”, in which he is advancing the argument that the basis of language is informed by the way we perceive and name colors. The book was translated into 8 languages and was selected by the New York Times, The Economist and the Financial Times as one of the best books published in 2010.


Water, water everywhere, and not a hint of blue

Even if you haven’t read the Homeric epics of the Iliad and the Odyssey, you must have heard his famous, and enigmatic, description of the “wine-red sea”. Wine-red? Has anybody ever seen the sea in anything even remotely resembling this color? Could the famous blue of the Aegean Sea, where the Homeric events took place, ever be other than brilliant blue? Literary scholars struggled mightily with this strange depiction. Some attempts were so convoluted as to be laughable; none were persuasive.

Coming to think of it, another ancient document, based on oral folklore and epic poetry, was written at about the same time in history, the 5th century BCE. Yes, you guessed it: the Bible. Surprisingly, both the bible and the Iliad and Odyssey describe the sea in many ways, like “big and wide”, or “stormy”, or “silent”, or “resting from his anger”, but never blue. (All you Biblical mavens, hold the gotcha emails: The color “tehelet”, mentioned in the bible was wrongly thought to mean blue. It is now known to be the color purple, extracted from sea shells found on the beaches of Israel and Lebanon).

Let’s dig a bit deeper in historical times: in the ancient tablets of Ugarit ( 8th century BCE), where many of the biblical tales originated from, there is no mention of the color blue. In the stories about the myriad fights between the Canaanite god of the sea, Yam, and the god of the earth and thunder and rain, Baal, there are many depictions of the sea, but never its color. We can go even farther back in time. The linguist Lazarus Geiger noted almost a hundred years ago that ancient Indian epics dating to about four millennia ago, like the Mahabharata, describe the ocean in many ways, but never mention the color blue. And the same is true for ancient Chinese writings.

To compound the mystery, the colors red, black, and white are mentioned many times in the ancient manuscripts, and in the later one, like the bible and the Koran, green and yellow are mentioned as well. In fact, biblical Red is described in many of its hues (“argaman”– dark red, just like Homer’s sea, “shani”-pink, “siqrah”-deep red). And so is Green: olive green, grass green. But not a hint of blue. So what gives?


Early research

William Gladstone was a famous British prime minister at the beginning of the 20th century. But what is less known is that he was a classical scholar, and published a seminal 1700-page study of Homer’s epic poetry. In a 30-page chapter, he describes Homer’s strange choice of colors (sheep wool and ox skin as purple, honey as green, horses and lions as red). The sky is studded with stars, wide, having an iron or copper hues. But, not one mention of blue.

Gladstone concluded that ancient people simply saw the world in colors different from the way we see it. He theorized that the present capacity to experience colors is thanks to rapid evolution in the structure of the eye. This we know is unlikely, because the time span is too short. Bear in mind, though, that he proposed it as the idea of evolution was just getting under way. Lazarus Geiger, the linguist, discovered that in the modern European languages words for ‘blue’ are derived from ancient words for ‘black’ or ‘green’. Black and red predominated in the ancient texts of India. Later texts added yellow, green, violet and blue, in that order. This progression suggested to Geiger as well that some kind of evolutionary process was going on.

A few years later, a Swedish anatomist of the eye discovered that many people suffered from a hitherto unknown deficiency: color blindness. Presto: An ophthalmologist by the name of Hugo Magnus concluded that ancient people were all color blind in today’s terms, and with time, as the eye absorbed more colors, its sensitivity to them increased, and that newly acquired trait was passed on to subsequent generations. Today, we know that acquired capabilities cannot be passed on genetically.

Enter the anthropologists. They wanted to see how primitive cultures that lived with limited or no contact with modern civilizations perceive colors. And they found what they were looking for. In 1898, the psychiatrist W.H. R. Rivers went to the Torres straits islands, between New Guinea and Australia.

There he investigated the islanders’ perception of colors. He was astonished to hear the elders describe the sky as black, and a child describing the color of the sky as dark as dirty water. He and other anthropologists concluded that early humans and isolated cultures were not color blind. They see all the colors that we see, but consider them as simply hues of white or black or red, not worth inventing a special word for.


Modern Research

Rivers, the psychiatrist cum anthropologist said that “there must be something that caused those natives to see the brilliant blue as duller and darker than we see it”.

Enter neurobiology. Today, we know that this something resides in the brain. Deutscher believes that ‘black’ is a wider term for the islanders than for us, that they see blue as simply a hue of black. Is this unusual? Not at all. I see red in many hues. My wife sees peach, and orange and strawberry as distinct colors.

But there is another factor at play here. Scientists believe that it is not just a simple case of nomenclature; the islanders indeed perceive the sky a bit darker than we do. When we get used to seeing two hues as different colors, language trains us to see them as different entities. And the brain then exaggerates these differences, especially at the border areas between them.

And thus blue, which we perceive as lighter and totally distinct from black, is in reality probably a bit darker and closer to black. In a sense, the “obvious” distinction between black and blue is figment of our imagination. Modern neurobiological research is providing ample evidence for that.

Why were black, white, and red the first colors to be perceived by our forefathers? The evolutionary explanation is quite straightforward: ancient humans had to distinguish between night and day. And red is important for recognizing blood and danger. Even today, in us moderns, the color red causes an increase in skin galvanic response, a sign of tension and alarm. Green and yellow entered the vocabulary as the need to distinguish ripe fruit from unripe, grasses that are green from grasses that are wilting, etc. But what is the need for naming the color blue? Blue fruits are not very common, and the color of the sky is not really vital for survival.

This is truly fascinating. First, here is a totally unexpected phenomenon: language influencing brain function. But even more “disturbing” is the realization that the way we see the world is somewhat of an illusion, a product of a trick played on us by none other than our own brain. Which brings us full circle to the ancient Greeks and Plato’s allegory of the cave. He posited that reality is an illusion, it is like the shadows of cave dwellers cast on the walls of a cave by a fire at the cave’s opening. We, standing outside the cave, see the shadows only, not the real occupants. Reality, as we see it, is illusory.

Mind boggling.

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Dov Michaeli, MD, PhD loves to write about the brain and human behavior as well as translate complicated basic science concepts into entertainment for the rest of us. He was a professor at the University of California San Francisco before leaving to enter the world of biotech. He served as the Chief Medical Officer of biotech companies, including Aphton Corporation. He also founded and served as the CEO of Madah Medica, an early stage biotech company developing products to improve post-surgical pain control. He is now retired and enjoys working out, following the stock market, travelling the world, and, of course, writing for TDWI.


  1. When philosophy and science interweaves, it brings forth confusion and wonder.hee It’s quite fascinating the way the world worked back then, and how we operate it right now. There’s so many things that just becomes clearer and quite astounding. And I sincerely believe that what we know right now is just a byproduct of our biases and belief, in short just a made up reality in our heads.

  2. “they see blue as simply a hue of black. Is this unusual? Not at all. I see red in many hues.”

    When I was in the Navy I always wondered why my “navy blue” uniform was obviously black.

  3. Pardon the edit, but the cave analogy of Plato went even further than you’ve taken it. The observers are in the cave, watching a shadow puppet show (of sorts) on the wall. The reality is behind them, where the people enacting the show stand with fire behind them, but the REAL reality is outside the cave altogether, where the Sun (metaphorical and figurative in this case), represents the Good, Truth, or even God, if you will (though that’s my Christian interpretation, but the leap is a small one, if there’s even a leap to be made). In other words, the light that helps cast the shadows in the cave is closer to truth, but the real Truth is the light of “day” outside (so the observers are doubly blind: they can’t see the farce enacted properly, or know that it’s a farce, and they’re also separated from the Sun of the Good, Truth, God, etc.). Your (probably accidental) changing of the analogy makes it seem like we’re all outside, which was certainly not something in the original analogy of Plato (the rare individual is the one who turns around, walks past the mummer show, and goes outside to see the Sun, Truth, God, etc.). Thanks for the article, though. I heard some girls talking about how the lack of mention of “blue” in the Iliad and Odyssey are “proof” that evolution has occurred since then in color perception, but I failed to buy the statement, and came searching for second opinions. You seem to be of the same opinion (evolution), but you also suggest other possibilities. I suppose it’s possible that the word for “red” doesn’t mean the same thing for us as it did for the ancients, but… I will continue to think on this one (a little).

    • (PS — the picture you included of Plato’s analogy is accurate, even if the description was a just a tad off — the observers are in the cave, there’s the show behind them, and the “ascent to the sun” (or the way out of the cave) is at the top of the picture. Love philosophy, and Plato is, of course, one of the best. :) Thanks again for your thoughts, hope you don’t mind the correction. You know way more than me about lots of stuff; I just happen to know a bit about philosophy.