I wonder if the interference-based-blue of the morpho butterfly evolved because it's difficult to make blue pigment for some reason having to do the chemistry of our biosphere, or if it's an evolutionary response to humans who may have captured the blue ones and ground them up for pigment (much like we did with https://en.wikipedia.org/wiki/Tyrian_purple snails).

I'm not aware of any record of us having done so, but it's absolutely the kind of thing we would do, and there's much more pre-history than history when it might've happened.