The "Rayleigh Scattering" comic is really spot on.
Air is blue. The reason air is blue is blah blah blah physics, see the article we're all commenting on, but at the end of the day air is blue. We don't demand the same elaborate physics questions for why a ripe banana peel is yellow.
Though is some cases it is a very interesting question, like why gold and copper the color they are instead of being boring and silvery like all the other metals?
Not really. If the explanation was "air is blue" then the naive expectation would be that sun would appear blue against blackish background, basically the image of sun is being filtered through the atmosphere; if sun is white and air is blue then white filtered through blue should be blue? But sun appears yellowish against blue background. So clearly something different is going on.
But a banana is yellow for a very different reason (and a much easier to explain reason) than why the sky is blue. And air isn’t blue, because it’s red at the end of the day?