4 ms·

Assuming this[0] is accurate, it looks like solar irradiance reaching the surface is pretty flat from mid-blue up to red, including green. I would guess either

• adrian_b 4y ago
  The most successful aquatic phototrophs, e.g. brown algae and diatoms, absorb a much larger fraction of the solar light, by having complementary pigments that transfer the energy to chlorophyll. On the other hand, the terrestrial space is dominated by the green plants because here the problem is not absorbing more of the abundant light, but avoiding overheating from absorbing too much light (because the efficiency of photosynthesis is low, so most of the absorbed energy becomes heat, and not only there is much more light in air, but also the cooling is more difficult than in water).