[SunkenCiv]

Indigotin powder

Laura Longo

[jimtorr]

I am sometimes puzzled when “experts” don’t realize that many cultures from the neolithic know stuff beyond simple food acquisition. I think they discount the tens of thousands of years of their ancestors experience.

[Cincinnatus.45-70]

Thanks, SunkenCiv.

[Harmless Teddy Bear]

But some people argue that humans could not "see blue" until very recently.

It is just a very hard color to produce.