I'm skeptic to think that the moon colors have something to do with the mating. I think it has something to do with the tide patters a full moon creates on the reefs that triggers the Mandarin to breed. I think the diver should study the mandarin breeding when there is a cloudless full moon and a cloudy full moon and see if there is a difference in the amount of spawning happening.
Of course that would mean, due to the size of our tanks, the moons gravitational pull wouldn't play an effect on our tanks and therefore it would be hard to use it as a trigger for spawning.
Of course that would mean, due to the size of our tanks, the moons gravitational pull wouldn't play an effect on our tanks and therefore it would be hard to use it as a trigger for spawning.