At one point or another, we have all seen a rainbow. But, although they are fairly common occurrences, it is remarkable how little most people actually know about rainbows.
In fact, most people couldn’t even name the 7 colors of the rainbow in order. If you’ve ever tried closing your eyes and name those colors in the right order, you’d have found that it’s a lot harder than it may seem to get it right.
The most common mnemonic techniques are to either memorize the initials for each color in order (VIBGYOR) or turn it into a name by reversing the order (ROY G BIV).
Sunset is still my favorite color, and rainbow is second. – Mattie Stepanek
What Are The 7 Colors of The Rainbow in Order?
The white light that emits from the sun can be broken down into the 7 colors of the rainbow in order:
So, just memorizing the first letter of each color is perhaps the best way to remember them.
There is, however, not a universal agreement of this. Most notably, science and science fiction writer and thinking Isaac Asimov (1920-1992) said the following about it:
It is customary to list indigo as a color lying between blue and violet, but it has never seemed to me that indigo is worth the dignity of being considered a separate color. – Isaac Asimov.
Despite what Asimov said, it seems to have become generally accepted that the colors of the rainbow are seven and that they indeed include the color indigo. This is probably because more ordinary people who look at a rainbow (both directly or a photograph or video recording of one) will be able to see and identify the seven colors.
|Color Of The Rainbow||Color Wavelength (nm)|
|Violet||455 – 390|
|Blue||492 – 455|
|Green||577 – 492|
|Yellow||597 – 577|
|Orange||622 – 597|
|Red||780 – 622|
|Red||780 – 622|
But there’s a lot more to know about the colors of the rainbow other than just the order.
What Is The Origin Of The 7 Colors of the Rainbow?
17th Century English theologian, astronomer, and mathematician, Sir Isaac Newton (1642 – 1726 or 1627), was the first person to realize that it was possible to see the view all the full-color spectrum by breaking apart white light.
The most natural way to create a prism would be to use raindrops. That is why a great way to observe the visual spectrum is by looking at a rainbow.
Even a quick look at the full-color spectrum makes it evident that the colors are not discrete categories. Looking closely at it, you will notice that each color bleeds into the one next to it.
So, the color violet bleeds into the color indigo, the color indigo bleeds into the color blue, the color blue bleeds into the color green, the color green bleeds into the color yellow, the color yellow bleeds into the color orange, and the color orange bleeds into the color red.
What what’s on either side of the spectrum? Ultraviolet or UV is violet’s neighbor and infrared or IR is red’s neighbor.
Because all the colors bleed into each other, settling for seven colors may seem a bit arbitrary. Contemporary observers may not question this, though, because we have accepted that there are seven colors. That’s what we’ve been told so it can be hard to see anything else. But, deciding that there were only seven colors and, therefore, ignoring everything that is “between” each of these colors has very deep historical roots.
What’s The History Behind The 7 Colors of the Rainbow?
The fact that we have settled for 7 colors is no accident. The number 7 has a long history in Western culture.
It all began in Ancient Greece. Back in the 6th century BCE, a mathematician called Pythagoras (c. 570 – 495 BCE) believed that numbers were intricately linked to the real world. For him, numbers weren’t just abstractions but had almost magical qualities.
It was Pythagoras the first one to apply numbers to pretty much everything that happens in real life. For example, he discovered that the seven musical notes could also render as mathematical equations (or at least he gets the credit for it).
He observed that most phenomena in nature or, more broadly, in the real world had something to do with the number seven. In Pythagoras’s thought, mathematics and mysticism are combined. Pythagoras’s thought was hugely influential in the Classical world among philosophers.
If you are not sure if any of this is still relevant in the 21st century, just consider how many different concepts are ordered using the number seven, many of which go as far back as the Ancient world.
For example, we still talk about the Seven Wonders of the World, Christians believe in the Seven Daily sins, there were seven dwarfs in the Snow White fairy tale, etc. But not only that, there are also seven days of the week. Everywhere you look, you will see the number seven.
Why Are There 7 Rainbow Colors?
The key fact here is that Isaac Newton was an admirer of not only Pythagoras but also of anyone who was influenced by his thought throughout the years, particularly the likes as Philolaus (c. 470 – c. 385) and, particularly, Copernicus (1473 – 1543).
This influence can be seen in how Newton’s thinking on the full-color spectrum evolved. Initially, the English thinker only saw five colors in the spectrum in the following order: red, yellow, green, blue and purple. He only added orange (between yellow and red) and indigo (between violet and blue) after he considered Pythagoras’s link between music and color.
Because, as Pythagoras thought and has been accepted ever since, there are seven music notes, then there should be seven colors. Obviously, there are more colors than those seven but they are all the result of combining two or more of those main seven colors.
So, as you can see the history why there are seven colors in the rainbow is very complex, very long, and very old. But it is also surprising because it includes elements of math, numerology, and, even, music. Although most people have accepted the seven colors as fact, in Isaac Asimov’s estimation, indigo should be removed and the rainbow should just have six colors. So, can you name the 7 colors of the rainbow in order now?