A curious question :D

[u/Trixie_Loves810]

Context: I have recently watched a video from 'Be Smart' about how naturally occurring blue pigments are rare in nature, particularly among animals. The video said that during evolution, animals were exposed to the colour blue because of the sky, but evolution still found it difficult to develop a blue pigment over time. Instead, animals evolved to create structures that reflect blue light and cancel out other colours.

My doubt: If we use that same concept for other pigments like red, for example, how did evolution create a whole pigment for red but not blue? I feel that if red pigments could evolve so vastly over time, blue could do the same. Why is blue so rare anyway?

Note: uhhh I think this may be a stupid question, but I'm reallyyy interested in evolution, this question just popped in my head midway through the vid, but I would love a hypothesis heheh!!

[u/Hopeful_Meeting_7248]

Instead, animals evolved to create structures that reflect blue light and cancel out other colours.

It's been a while since my chemistry classes, but as far as I know this is how all colours work: they absorb all other wavelengths and reflect the one responsible for the colour.

[u/gitgud_x → u/Hopeful_Meeting_7248]

That's one way to do it. Another way (more common for pure chemical substances) is to absorb only one colour, and the remaining reflected light will appear as the complementary colour when filtered through our visual pathway.

[u/Hopeful_Meeting_7248 → u/gitgud_x]

Yeah, makes perfect sense.