It would make a good title for a novel, but truth is often stranger than fiction and the story of blue lives up to that saying. Probably one of the most common questions asked by young children with inquiring minds is: “Why is the sky blue?” The true answer is not at all simple, but put simply, the interaction between sunlight (so-called “white light” containing all frequencies) and gas molecules in the atmosphere results in the scattering of different frequencies of light to different extents. The shorter wavelength blue light is scattered more strongly than red, about 10 times as much, so we see more of the blue wavelengths. Try explaining that to your 5-year-old.

Blue is, in fact, a surprisingly rare color. The Iliad, the epic poem of the Trojan War, penned by the eighth century BCE Greek Homer, runs to 704 pages. It goes to great lengths to avoid mentioning colors, but black appears 170 times, white 100, red 13, yellow 10, green 10, and blue not at all (someone had time on their hands!). This from a country famed for its blue waters. In fact, blue gets no mention in historical Icelandic texts, ancient Indian sagas, old Chinese writings, or the Hebrew Bible. In the 1800s, linguistic scholars became interested in the order in which color words began to appear in language. They commonly found the following order: black, white, red, yellow, green and, lastly, blue. While there was some deviation in the middle order, red was always the first color (after black and white) and blue always the last, whatever culture they studied. This is surprising as the sky is often blue, always there, and arguably more obvious than red, but no one mentions this. There are two theories as to why the order is as it is. The evolutionary hypothesis relates to the need for words; black and white are obvious leaders—night and day, dark and light. Red is the color of blood, yellow and green possibly for ripe and unripe food. A second theory postulates that a word did not appear until a particular color could be made, blue being the most difficult.

The Japanese word for blue is ao; aoi kuruma is a blue car, but the color word describing a green apple is also ao—ao ringo; a green traffic light is ao shingo and green juice (as from vegetables) is ao jiru. Originally, the Japanese language contained only four color words—black, white, red and ao; the catchall ao covered everything from green to indigo until the early 1900s, when midori was introduced for green. The language of the indigenous people of the Ivory Coast recognizes only black, white and red. Russian, however, has different words for light blue and dark blue, as does Turkish and modern Greek, while Western nations have the one word covering everything from baby blue to navy blue. Widely separated languages such as Dani, spoken in Papua New Guinea, and Bassa, spoken in Liberia and Sierra Leone, only have two terms for color, which roughly translate to cool or warm. Like old Japanese, the Himba people of Namibia and another Papua New Guinea tribe, the Berinmo, inhabiting widely different landscapes, have one word for both green and blue, as does old Welsh.

My money would probably be on the evolutionary theory. If there is a need, especially an urgent one, to describe something accurately and be immediately understood, you need a specific word for it. If your group is about to be attacked by a predator, it might be more useful to shout, “Run! Tyrannosaur!” rather than take the time to describe it.

The Himba people of Namibia have difficulty distinguishing blue from green, which to Western peoples is obvious most of the time. In contrast, they can discriminate between many shades and types of green. Perhaps a need to talk about plants and trees encouraged this. Peoples of Scandinavia, Greenland and Iceland have many words for snow (controversy rages over exactly how many—some say 50, but 10 or more is certain), while we have two or three. Presumably, the climate produces a greater variety of conditions there between which it is important to distinguish, as it does in Doric, the dialect of northeast Scotland, a very damp place. Doric has 20 words for rain and related conditions.

Research by neuroscientists in Britain has revealed that the brain has a big part to play in how language and words influence us. It was found that long-term exposure of immigrant Greeks to everyday English blurred the distinction they perceived between their hereditary two-blue structure, compressing it into the one-color category used in English. It appears language trains the brain to distinguish color. There is a feedback loop: the brain creates language and the colors language identifies have an impact on brain function. Our perception of color is an illusion and our brains take an active part in creating it.

With a few exceptions, all the colors we see reflected around us are leftover wavelengths after the objects involved have absorbed all the other wavelengths. A blue car is blue because the pigment in its paint job absorbs the red, orange, yellow, green, indigo and violet wavelengths. I use those color names courtesy of Sir Isaac Newton. He split white light coming through a hole in the shutters of his bedroom into the familiar spectrum with a glass prism and, fairly arbitrarily, named them so. The familiar mnemonic by which all British schoolboys remember them uses the initial letters of “Richard of York Gave Battle In Vain” (ROYGBIV). Richard III indeed lost the Battle of Bosworth Field and ended up under a parking lot in Leicester. There were those who accused Newton of “inventing” unnecessary colors to make the total seven; five were reckoned to be more realistic. Newton, they said, artificially created seven colors to accord with the seven days of the week, the then seven known planets, and the seven notes in the musical scale. Newton, however, championed orange and indigo, which I’m sure pleases Bronco fans.

There is so much more to be said about the strangeness of blue. Why, for instance, are there no land-based vertebrates, no birds nor animals, that are pigmented blue? “But what about Jays and Bluebirds?” you say. That’s another story entirely.

© David Cuin 2021