Looking back gives us a glimpse at how those early people saw the world around them.

We'll also answer that age old question: which came first orange?

Orange the fruit or orange the color?

I'm Doctor EricaBrozosky, and this is Otherwords.

The human eye can perceive millions of slight gradations of color.

But unless you're a designer or an artist, you probably only regularly use about 10 or so color words.

And they are remarkably similar across all cultures.

A landmark study by Brent Berlin and Paul Kay found that people across the world develop their words for colors in more or less the same chronological order.

For example, if a language only had two words for colors, they were always black and white.

If a language had only three color words, they were black, white and red. Yellow and green came next in either order, then blue, brown and so on.

This hierarchy closely matches human psychology.

After all, what could be more visually fundamental than the dichotomy between light and darkness and were hardwired to have a strong emotional reaction to red as it has a lot of survival significance from food to sex to violence.

Blue is surprisingly far down the list considering it's most people's favorite color.

But actually, due to a chemical quirk blue is very rare in nature, except, of course, for the sky, but you don't really need a word to help identify the sky.

Which sky do you mean? Oh the blue sky.

The English word white can be traced all the way back to the Proto-Indo-European root "kweit-" which meant to shine.

Black similarly goes back to the PIE "bhleg-" which meant to burn a reference to the color of what's left after burning.

Red is unique and that is the only color that has an PIE root that just meant the same thing, red.

Although it may have been used to describe anything that had a warm or interesting color.

Yellow came from the PIE "ghel-", which also meant to shine and gave us many related words like gold, glimmer glow and gleam.

Green comes from the pie"ghre-", which meant to grow for its obvious connections to plants and also gave us grays and grass.

Interestingly, even though humans can perceive more shades of green than any other color, we just use one word for them all.

Think about it.

How many different kinds of red can you name compared to different kinds of green.

The reason is probably that even though our ancestors were surrounded by green or rather because they were surrounded by green, it's just not that interesting to us.

A 2016 study by Hannah J. Haynie and Claire Bower found that humans across many different languages have an easier time communicating warm colors than cool colors.

This color wheel for instance, has twice as many common color words on the warm side than the cool side.

To understand why, just picture with the world may have looked like to our early ancestors.

Which things in their field of view are worth talking about, the cool colored ones or the warm colored ones?

Perhaps for this reason, the word blue has been traced back to the PIE root "bhle-" which meant yellow.

There simply wasn't a need to describe the color blue until much later on when humans started making dyes and paints from rare materials like lapsi lazuli.

Orange was pretty late to the scene. The old English term for the color between yellow and red was "geoluhread", which literally meant yellow, red.

But then sometime around the the 15th or 16th century, Portuguese merchants began importing an exotic fruit to Europe known by its Sanskrit name, naranga.

This came to be naranja in Spanish, arancia in Italian and orange in French.

The latter two likely dropped the n at the beginning through a confusion about where the article ended.

It's the same way we got an apron from a napron and a nickname from an ekename.

Over the next couple 100 years, people went from saying things were orange colored or the color of an orange to just saying they were orange.

So there you have it, the fruit came first.

But we're still living with the effects of not having a proper name for the color for a long time.

It's why this is called a redhead and this a Red Robin, even though they're both clearly the color of an orange.

Brown comes from the PIE "bher-", which meant bright, possibly in the sense of polished wood.

Indeed, it also gives us the word burnished.

The animal that we today call a bear went by a totally different word prior to the middle ages.

But since it was considered dangerous to even mention the fearsome beast by name, ancient hunters came up with a euphemism "bero" which meant brown one.

They were so superstitious. In fact that the true old English word for bear is now lost to history.

Purple is one of the few common color words without a PIE root.

It comes from the Latin "purpura," which referred to a certain shellfish that was ground down to make a distinctly colored dye.

Because of its vibrance and rarity, purple became very popular with the wealthy and powerful and is still associated with royalty today.

It wasn't really until humans became proficient artists that we started adding colors or vocabulary by the hundreds.

Most are either based on the source of the pigment, like stones, plants and insects or to what the color reminds us of whether it's the sky, the birds or a beverage.

So how many unique color names are there?

It's hard to say, but it's definitely in the hundreds, if not thousands.

Some have long histories dating back to the beginning of civilization and some were made up recently by crayon marketing departments.

You may not need more than 10 or so on a day to day basis.

But the explosion of words shows that color has gone from something that we just used to survive to an integral part of expressing ourselves and making our imaginations a reality.