When we glance at the sky to see that it is green or crimson what we are in reality seeing is the sun's light reflected (scattered) from little particles inside the atmosphere (these can be brake dust particles, water substances, CO2 therefore forth). The angle the fact that light will be reflected depends upon what light particles' (photons') strength. Highly enthusiastic (short say length) light will be existing at large aspects. This is the blue light. For mid day time, when the sun is straight above your face and you take a look at other course (towards the horizon) the sunshine that you will find will only end up being the light that may be deflected by a large position - hence the blue skies. In the event you look towards sunlight at the middle of day (DON'T do it with out protection) you will notice that the heavens has a kind of yellowish white-colored color, mainly because what you are seeing then can be described as mixture of spread light and light directly from the sunlight - which in turn contains most wavelengths. Later in the day and start the sun is definitely directly on the horizon and the light that you are seeing only has to be dispersed at a small angle so that you can see it. Reddish colored light is definitely not energetic and scatters at low angles, which means red heavens. If you were to look straight above you at this time you would realize that the skies is without any red color and only remenents of blue remain. Which is light which is scattered at large angles, just this time sunlight is coming and it's lumination is existing from particles directly overhead. It is a recognized phenomena that all polluted cities (like M. A. should you live in the USA) possess beutifully colored sunsets. This is because light is far more scattered more intensily by the abundance of small particles in the air. Whenever we had a clean, atmosphere-less globe (such because mars) each of our skies might have been 100% black and the sole source of mild would have been the sky and light shown from the ground.