Colors Of The Rainbow

Colors of the rainbow

We’ve learned about rainbows ever since we were kids. We’ve drawn a multitude of them and we’ve seen plenty of them. However, if you were to be asked what exactly constitutes a rainbow, how confident would you feel in your ability to answer that question? If your answer is not exactly positive, then read on to know more about the arch of many colors that Mother Nature puts on display for us to see on rainy days.

What is the rainbow?

In order to clearly understand what is a rainbow, we need to take a step back and get acquainted with a prism. Take a triangular piece of glass or plastic and shine a narrow trip of white light onto one of its sides; what you will see, is the same array of colors that characterise a rainbow. The reason behind it is explained with simple physics.

Every material has a distinguishable characteristics called the refractive index. When light travels through the air and goes through the prism, the light comes out from the other side of the prism bent (refracted), because of the difference in refractive index between the air and the glass. Colors have different wavelengths and as such, they bend at different angles, thus forming a rainbow.

In nature, falling raindrops act as little prisms. Sunlight enters one side of the droplet, it’s refracted and then reflected off the back of the inside of the raindrop. As the light comes out of the other side of the drop, it’s reflected again and it forms a beautiful rainbow.



How many colors in a rainbow?

Newton (1672) originally divided the spectrum of light into five main different colours, though after admitting he was unable to clearly distinguish colors, he included two more to the list, thus officially characterising the rainbow with seven main colors.

In reality, the number of wavelengths in a rainbow is endless. However, the human eye is able to distinguish approximately 10 million colours, thus making Newton’s statement ‘just a little’ off. 

Colors of the rainbow

Obviously, most of those 10 million colors don’t have names and are simply identified by their wavelength. They are all different, yet to the human eye, large amount of those wavelengths look the same.

Newton himself thought so. He listed seven main colors, namely red, orange, yellow, green, blue, indigo and violet; however he once said, “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. To my eyes it seems merely deep blue”. Most men would agree with him, I believe.

Rainbow color order

As we’ve learned, colors are refracted according to their wavelength. As such, the color with the longest wavelength will bend with the widest angle and appear as the first color on the rainbow from the top. The rest will follow with decreasing wavelengths.

The first color is red, followed by orange, yellow, green, blue, indigo and violet.

When do rainbows appear?

Rainbows appear when there’s mist in the air, usually after a storm. They always form directly opposite the sun, depending on the observer’s perspective, meaning they only appear when the sun is low in the sky. Thus your chances of seeing a rainbow are in the later afternoon, when the sun is on the west and the arch is on the east, and early in the morning, when the opposite is true.

Rainbow flag meaning

Gilbert Baker, born in Kansas in 1951, was an openly gay activist who moved to San Francisco as an Army draftee in 1970. After an honorable discharge, he decided to stay in the city as he’d rather pursue his dreams as an artist than go back home. He taught himself to saw and began to spend his time making the clothes that he loved so much.

In 1974, Baker met Harvey Milk, and his life changed forever. Three years went by and Milk was elected to the San Francisco Board of Supervisors, which was a big deal as that identified him as the first openly gay individual to hold a significant position in office in an American metropolis. He won the election and decided to challenge Baker to come up with a symbol to represent gay pride for the community, as the alternative of the time, the pink triangle, had been reclaimed as a symbol of remembrance and protest against persecution.

Braker quickly got down to work, dying the fabrics himself and stitching them all up with the help of volunteers to make the representing flag with 8 colors: hot pink, which stood for sexuality, red, orange, yellow, green turquoise, indigo and violet.

The first time the flag was flown was in the 1978 “Gay Freedom Day” Parade in San Francisco. When he approached a company to mass produce the flag, however, he got bad news, as hot pink fabric was not available, though they were already selling a seven-striped version of the rainbow flag. Baker went for that option, however not for long, as just one year later, he decided to eliminate the indigo stripe and get an even six-color flag to mass produce.

Almost 40 years later, things have slightly changed. Hot pink fabric is now readily available and the flag has been restored to the original eight colors, the symbol of the LGBTQ community.

Published by Carla Cometto on 16 September 2017