Alternately I liked the high physicist take on :"Why is the sky blue?"
Answer: That air is blue.
Not rayleigh scattering etc etc.
Reason: why is anything the colour it is? Because that is the colour of light that comes from it. You don't ask why an orange is the colour orange, or a good strawberry is red, you just accept it is.
And then if you want to go into the "why is anything a particular colour?" then it isn't just the sky we're talking about.
Great, that settles the old question: "Is an orange in a completely dark room still orange?".