What would the results of this experiment look like if the pigments that drive photosynthesis in the algae were to absorb most strongly at 500 nm and 560 nm?

Attached is the experiment details. I found the exercise on the internet.

The pigments of the algae, according to the experiment, absorb the most strongly around the violet-blue and red parts of the spectrum and so photosynthesis is the most efficient when the algae are under such wave lengths. The results were that more oxygen-seeking bacteria gathered around the algae that were under such wave length because there were more production of oxygen.
If the pigments were now to absorb most strongly around the 500 nm to 560 nm, the bacteria would gather the most around the algae under such wavelegth (green light).

Enchinoderms im positive

The answer is one amu.