Even in hot of the mid day sky looks in blue color why?The blue color of the sky is due to Rayleigh scattering.
Light from the sun appears white but it actually consists of many different colors. We.We can see all these colors available in the light in rainbow.When white light from the Sun travels through the earth’s atmosphere, it collides with particles of air.Each color has different wave lengths.
Wavelength of blue color is smallest and red light is longest, the blue light is scattered most and the red light is scattered least.High wave length lights are pass through and low wave length lights are absorbed by the gas molecules in the air.
This gas molecules reflect the lights in different directions.The scattered blue light reaching the eye gives the appearance of a blue sky.
During the sunset high wave length lights are passing through the atmosphere more than blue light scattered,thats why we are seeing red or orange color during the sunset.