[frumiousirc]

Well, plants and eyes long predate apes.

Water is most transparent in the middle of the "visible" spectrum (green). It absorbs red and scatters blue. The atmosphere has a lot of water as does, of course, the ocean which was the birth place of plants and eyeballs.

It would be natural for both plants and eyes to evolve to exploit the fact that there is a green notch in the water transparency curve.

Edit: after scrolling, I find more discussion on this below.

[seba_dos1]

Eyes aren't all equal. Our trichromacy is fairly rare in the world of animals.