Why does the sky change color?
Because maybe of the sun, and plus of the diffrent chemicals released into the air. There is sun radiation coming from space also, and as it hits the atmosphere, it changes colors
Your eyes are playing tricks on you XD
Gas, condensation, etc. pollution
Because it wants to
Because the sky is an emotional person, who has feeling... Sometimes he's happy sometimes he's sad :/ he's pretty bipolar...
Because the sun goes down at some point