text: what is the color of the air?   air of course we can not see, so at least to humans it seems to be clear. as for the sky... http://www.sciencemadesimple.com/sky_blue.html http://www.everything2.com/index.pl?node=why%20is%20the%20sky%20blue%3f  "contrary to popular belief the sky is not blue because of refraction.  refraction is not a significant enough effect to have this sort of affect although it can change the apparent position of the sun  the real reason why the sky is blue is due to a phenomenon known as rayleigh scattering whereby blue light is absorbed by gaseous molecules in the atmosphere ( ie air ) and then re-emitted in a random direction.   thus as white light from the sun travels through the atmosphere the blue light is scattered away from its original direction of travel, and some of it is scattered down towards us which causes us to perceive the sky as blue.   this is also the reason why the sun is yellow."