Why is the sky BLUE in the DAY, PURPLE at DAWN and BLACK at NIGHT?

The color of the sky is caused by spreading of white sunlight despite the fact that broadcasting itself  in the atmosphere. This light is white since it holds all frequencies of visible light. These molecules are barriers to the light. They are shown to be the size of diverse light waves and cause these to scatter, bounce. So when they do scatter and bouce, the colors of the scattered light waves turn out to be visible in the sky. Depending on the width of the atmosphere as well as amount of particles enclosed in it the sky turns from blue (shorter waves) to yellow and finally red (longer waves). 

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 Meaning at dusk and dawn which is the thickest atmosphere or the highest density of particles. In addition to that under extraordinary situations when clouds start throwing shadows you visualize other colors being scattered, similar to purple or pink.

 physicists tell us

because blue light in the sun's rays bends more than red light.  But this extra bending, or scattering, applies just as much to violet light, so it is reasonable to ask why the sky isn't purple

 

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  A common prism disclose, sunlight is made of all the colors of the rainbow.  When light from the sun enters Earth's atmosphere, it is scattered by molecules in the atmosphere ( Mainly nitrogen and oxygen) These molecules are barriers to the light. They are shown to be the size of diverse light waves and cause these to scatter, bounce. So when they do scatter and bouce, the colors of the scattered light waves turn out to be visible in the sky.   Shorter wavelengths like Violent and blue are scattered more than longer wavelengths like yellow and red .

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So as we look in a direction of the sky away from the sun, to visualize those wavelengths that are turned the most.  Which is Depending on the width of the atmosphere as well as amount of particles enclosed in it the sky turns from blue (shorter waves) to yellow and finally red (longer waves).  Meaning at dusk and dawn which is the thickest atmosphere or the highest density of particles. In addition to that under extraordinary situations when clouds start throwing shadows you visualize other colors being scattered, similar to purple or pink.   

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  The light of day is in fact a complex spectrum of numerous different wavelengths, however it is conquered by light with wavelengths between 400 nanometers which is violet and 450 nanometers which is blue and a nanometer is a billionth of  1 meter. In other words  the mind plays a trick on our mind so we therefore perceive as red and green turn into yellow  but if the sky's mixture of violet and blue extract the same cone reaction as pure blue plus white light, which is an equal mixture of all the colors. 

  Your eye can't tell the difference between that complex spectrum and one that is a mixture of pure blue and white   

In a nutshell light approaching from the Sun has to pass through layers of atmosphere around the earth along with in that course, this light becomes scattered by dust particles here in atmosphere plus depending on which color is mostly scattered the space around sun as seen from earth come into view to be of that color.  

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