So that begs the question of all the wavelengths .. why green? (Yes yes i know WHY scientifically) but not from an evolution design point.... the green is right smack in the middle of the visible wavelengths, also our strongest visual color.
If you know "why" scientifically, then you do know why.
The fact is that the plants - which evolved first, before animals - use the wavelengths on either side of the green. They presumably do so for different processes, requiring different energy levels which just happen to correspond to those frequency bands, and there is no important photosynthetic process which corresponds to the energy level of green (E=h?).
The photoreceptors in the human (or ape) eye developed later (much later,) and in all probability share the behaviour of the photosynthetic pigments. As we know, reactions corresponding to ultraviolet wavelengths although some are useful (synthesis of Vitamin D) are more likely to be damaging to tissue, whereas infra-red wavelengths generally carry too little energy to be useful at all, so defining a "window" of important frequencies.
A particularly interesting fact is that many animals - and some humans - are red-green colour blind and lack that green sensitive pigment, so it is actually an evolutionary novelty - and presumably strong advantage - that we do respond, and do so well, to green, due to a "gifted" mutation in the red receptor gene.