[NoSorryCannot]

The reason pigments or anything else is blue is also because of physics.

[pengstrom]

While true, it might be worth noting that if you grind iridescent blue material it will loose its color. Pigment will not.

[dTal]

https://xkcd.com/1818/

[Agentlien]

A friend of mine once claimed that the sky wasn't blue. I challenged him, expecting some argument about physics and Rayleigh scattering.

Instead he looked at me and, with a straight face, said "it's the spy satellites which are blue. And there are very many."