The Color Blue

Podcast Transcript

Colors are something that we are all familiar with. The colors are among the first things we teach children.

What if I were to tell you not every culture has the same colors? By that, I don’t mean they have different words for colors, but some very basic colors have no words at all.

For some reason, blue is the color that divides many cultures.

….And that isn’t the only interesting thing about blue.

Learn more about the color blue and what makes it interesting on this episode of Everything Everywhere Daily.

I’m going to start this episode with a very simple question: how many colors are there in a rainbow?

You can probably quickly answer this question, and your answer would be that there are seven. You’ve learned the mnemonic when you were a kid ROY G BIV for red, orange, yellow, green, blue, indigo, violet.

Very simple.

However, if you look really closely at a rainbow, you’ll notice that there are obviously more than seven colors in it. There are gradients and changes between the colors. It isn’t as if nature had seven crayons and there are sharp divisions between the colors.

We say that there are seven colors because it makes it easy to comprehend what is happening in the visible spectrum.

In Western languages, particularly English, there are 12 basic color terms that are commonly found. They are based on the work of anthropologists Brent Berlin and Paul Kay, who proposed a universal pattern in the development of color terminology.

The colors are:

Black
White
Red
Green
Yellow
Blue
Brown
Pink
Orange
Purple
Gray

The 12th color is usually beige or turquoise.

These are considered basic because they are Monolexemic, meaning they are a single word, not compound like “light blue”; they are not subsumed under another color, like “crimson” is a type of red, and finally, they are commonly known and used across the speakers of the language.

However, these colors are not universal.

In fact, Berlin and Kay’s research found a trend amongst languages. As languages add colors, they tend to add them in a particular order.

Hunter-gatherers often have words for only a few colors.

The first words that any language will have for colors are for black and white, or more generally, between dark and light. The Pirahã people who live in the Amazon rainforest have no words for color beyond this.

After that, the next color that gets a word is red

The fourth word is usually green or yellow, and the fifth color is also green or yellow, whichever wasn’t chosen first.

Then, finally, comes blue.

There has been an internet rumor circulating that certain cultures are unable to see blue, which is why they lack a word for it.

This is not true.

Even in cultures without a distinct word for blue, people can still see blue just as well as anyone else. The difference is linguistic categorization, not visual perception. However, language does influence how quickly and easily people distinguish colors in tests. For example, people who linguistically separate blue and green can more quickly differentiate shades between them.

There is another interesting thing when it comes to blue.

Some languages use a single word to describe what English speakers would consider both green and blue. This is called the “grue” phenomenon, which is a portmanteau of “green” and “blue”.

This phenomenon isn’t something that appears in hunter-gatherers. This occurs in some very developed languages.

In Vietnamese, the word xanh refers to both blue and green, though modifiers can specify which one. xanh da tr?i for sky blue.

In ancient Japanese, the word “ao” used to mean both blue and green. While modern Japanese now distinguishes green, remnants of the old system persist, in particular, green traffic lights.

The Himba people in Namibia reportedly have no single word for blue and use the same term for blue and some shades of green, affecting how they distinguish those colors in tests.

There is another interesting thing about how languages adopt a word for blue.

There is some evidence of a loose correlation between a language’s latitude, particularly distance from the equator, and whether it has a distinct word for blue, but it’s not a straightforward or universal relationship.

The connection is influenced by environmental, cultural, and technological factors, many of which are correlated with latitude but not caused directly by it.

The big question, then, is why? Why did words for blue either not exist or were often lumped with green in some languages?

The rarity of naturally occurring blue objects in the ancient world may have contributed to their delayed naming. While the sky is blue, its color was often not linguistically conceptualized as distinct from white, gray, or black in early literature.

Homer, for instance, never used a word for blue; he famously described the sea as “wine-dark.” Blue dyes were also historically difficult to produce, and when they did appear, they were expensive and culturally specific.

There aren’t a lot of blue foods, and there isn’t a whole lot of blue in the animal world.

So, the short answer is some cultures didn’t develop a word for blue because there wasn’t a whole lot of blue in the world that was relevant to them.

Here I want to shift gears a bit and focus on one aspect of this: the development of blue as a dye and a pigment.

There were several colors that ancient people found very easy to create.

Black was trivial. Just rub the end of a burnt stick against a rock, and you have black.

Ancient people obtained yellow and red colors for rock art primarily from naturally occurring iron oxide minerals; red came from hematite, while yellow was derived from limonite or goethite. These minerals were ground into fine powders and mixed with binders like water, animal fat, or plant resin to create lasting pigments.

Green can be achieved through leaves or other plant parts that contain chlorophyll. White could be gotten from chalk if it were around.

In a previous episode, I covered how rare purple dyes were in the ancient world.. They were only created by a sea snail off the coast of Lebanon and were a prized commodity produced by the Phoenicians. It was so rare that purple became the color associated with royalty.

The color blue was also rare in dyes and pigments in the ancient world because the materials required to produce it were scarce, difficult to process, and often expensive.

Unlike the previously mentioned colors, which could be extracted relatively easily from common minerals, plants, or animal byproducts, blue did not occur frequently in the natural world in a stable or usable form. As a result, achieving a vivid, lasting blue was both a technical and economic challenge.

One of the earliest and most famous sources of blue pigment was lapis lazuli.

Lapis lazuli is a deep blue metamorphic rock that has been prized since antiquity for its intense color and rarity. Composed primarily of the mineral lazurite, along with calcite, pyrite, and other trace minerals, it has been mined for over 6,000 years, especially from the Sar-e-Sang mines in the Badakhshan region of northeastern Afghanistan.

This stone was ground into powder to produce a pigment known as ultramarine, which was extraordinarily vivid and durable, but also costly due to the rarity of the raw material and the labor-intensive process required to purify it. Ultramarine was so expensive that, centuries later in Europe, it was often reserved for painting the robes of the Virgin Mary in religious art.

One of the first cultures to regularly use a blue pigment in art was ancient Egypt.

In ancient Egypt, blue pigments were highly valued for their symbolic associations with the heavens, the Nile, and rebirth, and were widely used in art, statuary, and decorative objects.

Because natural blue minerals like lapis lazuli were rare and costly, the Egyptians developed one of the first synthetic pigments in history, known today as Egyptian blue.

This pigment was created by heating a mixture of sand, copper compounds such as malachite or azurite, and lime to high temperatures, resulting in a crystalline substance called calcium copper silicate. Once ground into a fine powder, it produced a bright, durable blue color that was used to paint tombs, ceramics, statues, and wall reliefs.

Egyptian blue was not only visually striking but also symbolically important, representing divinity, protection, and the eternal. It remained in use for over a millennium. Other Mediterranean cultures later adopted it as it was the easiest way to achieve a blue pigment.

For textiles and dyes, blue was even more elusive. The primary source was the indigo plant, which grows in warmer climates and produces a blue dye through a complex fermentation process.

Indigo dye is extracted from the leaves of the indigo plant through a complex process involving fermentation, during which the leaves are soaked in water to convert a colorless compound into indigotin, the blue dye.

After fermentation, the liquid is aerated to oxidize the indigotin, which then precipitates out as a blue paste that can be dried and traded. This labor-intensive process produced one of the most vibrant and lasting blue dyes known to the ancient world.

India became the principal center of indigo production for much of history, exporting the dye across Asia, the Middle East, and later to Europe via overland and maritime trade routes.

The Greeks and Romans used imported indigo as a luxury product, and during the Islamic Golden Age, knowledge of its production spread further west. By the 16th century, indigo became a highly sought-after commodity in Europe, rivaling woad, a native European blue dye.

European colonial powers, particularly the British, Dutch, and French, established indigo plantations in the Americas, West Africa, and South Asia to meet rising demand. In colonial India, British authorities transformed indigo into a major cash crop, often forcing Indian farmers to grow it under oppressive conditions, leading to revolts such as the Indigo Rebellion of 1859.

Indigo’s global importance declined only with the invention of synthetic blue dyes in the late 19th century.

The previously mentioned woad is a plant native to parts of Europe and western Asia, and it was historically used as a source of blue dye long before the widespread availability of indigo. The dye derived from woad comes from the leaves, which contain a precursor to the blue pigment indigotin.

To extract the dye, the leaves were first harvested, crushed, and formed into balls, which were then left to ferment. This fermentation process allowed the chemical precursors in the leaves to break down and eventually oxidize, producing a blue dye similar in composition to that of indigo, though generally less vibrant.

The Celts are famously said to have used woad to paint their bodies before battle, although the historical accuracy of this claim is debated.

During the Middle Ages, woad became a major industry, especially in regions like France, Germany, and England, where towns built their economies around its cultivation and processing. However, woad dyeing was messy and foul-smelling, due to the fermentation process, and woad generally produced a paler, less colorfast blue compared to true indigo.

When indigo began to be imported in larger quantities from India and the Americas in the early modern period, it gradually supplanted woad due to its superior quality and intensity..

My guess is that most of you have never given a second thought to the concept of blue. Yet it is something that some cultures don’t even have a word for, and for those that did, it was extremely rare to use in dyes and pigments for thousands of years.