why is the colour black not in the rainbow?

Answer 1

Black is all colors put together and white is the absence of color. That is why they are not in the rainbow.

Answer 2

As mentioned by others here, we see colours through light being reflected through a prism in the case of rainbows, the reflective element is the water contained within it and the density at which it shows it's refractive abilities..... the colours reflected are dependant on desinty of the water content and reflective abilities of the various densities... the colours you see are Primary (red, blue and yellow - also known as 'true' colours) and Secondary (green, purple and orange - this is where the primaries 'overlap' each other) ..... 'black' as we know it is all these colours together but with the absence of light - the moment you have any element within capable of reflecting light you will then see the refracted light as a 'black' changing hues and tones - ie. a blue/black or red/black - normally only seen when compared against a 'true' black - and again dependant on the refractive elements of the reflecting surface. White, as has been mentioned is light without colour - in other words no reflective surfaces for the light to reflect off of..... however there can sometimes be such faint reflective elements that these, as with the black, can only be seen when compared against a true white .....
The reason you don't see browns, or greys is because these colours are called 'Tertiary' (pronounced 'Tershiary') and are the result of all three primary colours mixed together or two primary colours mixed with one or two secondary colours, or two secondaries mixed with one primary and all the other variants there are - if you wanted to prove this to yourself just create a colour chart where you add a touch of colour combination bit by bit - you will, in every colour combination, eventually find shades of grey or shades of brown - they are only lightened or darked when white or black is added to them..... and since the presence of a rainbow shows how the reflective elements (ie the water droplet content density) have spread themselves there can never be a spread which overlaps more than once ....
hope this answer assists your understanding - it should also help towards explaining why different people can see the same colour in different ways - some see greens while others see blues or some see browns while others see reds - we call this colour blindness..... it's this reflective/refractive thing going on combined with the way the brain registers the signals being sent from the optice nerve.....

Answer 3

As many people here have said - as far as colour from sunlight is concerned black is not a colour, it is the absence of light. Rather like silence is not a sound - silence is the absence of sound.
A rainbow appears because the light from the sun is refracted (split) by the water raindrops. The raindrops act like prisms.
Light is electromagnetic waves across a range of frequencies. A frequency is the number of times the light beam "wiggles" (OK - technical term!) in a second. Think of waves at sea - they go up and down, they have peaks and troughs. Believe it or not - so does light. But very very fast.
We can see only part of the electromagnetic spectrum which also includes radio waves, infra red, ultraviolet, X-rays and gamma rays and other ranges that we cannot see.
Longer wavelengths (towards the red end of the spectrum) "bend" less through a prism than shorter wavelengths (towards the blue end) which is why we see them in the order we do in a rainbow.
Since black is the absence of light - that is, the absence of electromagnetic waves - it cannot appear as a colour in a rainbow.
Colour in this sense is different from the pigments we use in dyes and paints to make colours in the world around us.
If you are particularly interested in rainbows you could visit this site - http://www.realcolorwheel.com/rainbow.htm.
HTH

Answer 4

When you refract light, as in a rainbow, you split the white light into it's respective frequencies, red yellow etc., black is the absence of light so it's not present. I saw a rainbow at night once, where the light source was a full moon, the colours were very pale and it was framed by the night sky so was bordered by black.

Answer 5

A rainbow is formed when sunlight (which is white) is refracted through water droplets. These act as a prism, breaking the light up into the seven colours associated with a rainbow.

Black, as others have already stated, is the absence of light. White light, the source of a rainbow, does not contain "black light."

Answer 6

Black is not a colour! It is the absence of colour and white is also not a colour as it is the combination of all colours of the rainbow. Good question!

Answer 7

black is not a colour,white is not a colour,you may ask why taupe is not in the rainbow, its because that is not a colour either, it is a tone.
red blue green are primary colours,they make up the rainbow in tones of,if you wish to learn more about colour and the theory of colour, start with a colour wheel readily available at all good art supply shops, regards LF

Answer 8

rainbows are made when the light refracts(bends) off the water and divides the light into the spectrum of colours which makes up white light that we usually see. black is not part of this prsim and so therefore isnt shown. thats why we only see rainbows when it is raining and the sun is shining

Answer 9

black is not in the rainbow as most the coulours in the rainbow mixed make black... Its a dark colour which willc ontrast the bright colours of the rainbow

Answer 10

Question: Why is there an absence of the colors brown, black, and white in the
rainbow?
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Answer 1: OK. 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.

There are two more explainations here:
http://www.newton.dep.anl.gov/askasci/phy99/phy99125.htm

Answer 11

Black is not part of the prismatic light source that create the rainbow colours