Why is brown the only colour not in the rainbow?

Question

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Answer 1

Black, White are not in the rainbow either

A rainbow is white light seen through a prism (the prism being
the raindrops). The prism breaks the light into all the colors that make up white - so you do not see white because white is a combination of colors.
Black is an absence of light, so it is not in the rainbow. Brown is a combination of rainbow colors, so you do not see it in the rainbow.

Answer 2

That's an interesting question. To answer it, look at a fluorescent tube through a prism. Instead of seeing a continuous spectrum like a rainbow, which is what you see when you use a prism to split up sunlight or light from an incandescent bulb, you see three separate bands of red, green and blue, with gaps between them. Even though light from a fluorescent tube looks like daylight, your eyes are tricked. You can make white light by mixing all the colours of the rainbow or you can make what looks like the same thing by mixing these three primary colours. It's lucky that our eyes can't distinguish these two different things; colour TV and colour photography would be almost impossible if they required every colour the eye can distinguish, and not just the three primary colours. Your eyes can distinguish about 16 million different hues. That's why paint matching is so difficult. But brown isn't the only colour not present in the rainbow. Purple isn't either and there are several other examples. What they've all got in common is that they're all made by adding two primary colours which aren't adjacent in a rainbow. The orange you see in a colour TV image isn't the same orange you see in a rainbow. The rainbow orange is a pure colour with a definite wavelength. The TV orange is a mixture of red and green. You can split it into these two colours with a prism, but a prism won't split the orange in a rainbow.

Answer 3

That's a good question. I think it's because visible light consists of electromagnetic waves with wavelengths that fall in the range of about 480nm-700nm, and visible light that has a 700nm wavelength, for example, emits red light, while a shorter wavelength emits blue light (higher frequency). The rainbow always consists of ROYGBIV colors because those are the colors with specific "intrinsic" wavelengths. Brown light doesn't have a specific wavelength...instead, brown is a mix of different colors the rainbow. This is the best explanation I can provide...I think it's pretty accurate.

Answer 4

It's not the only color not in the rainbow. Although there are only a relative few prime colors, there are many mixtures of colors that can be done to create every color known.

Black isn't in the rainbow either. Black is a combination of many colors.

Answer 5

Brown isn't in the rainbow because it's a mixture of red, yellow and blue. If those 3 mixed in the sky, then brown would be there.

Answer 6

You got me on this one but if you go to
http://acept.la.asu.edu/PiN/mod/light/opticsnature/pattLight4Obj1.html This may help to understand the formation of rainbows