Lack of apparent response to the output of the green LED is more easily explained. First, the output intensity is very low at only 15 μmol·m2·sec and, second, the peak emission at 564 nm is just outside of the absorption bandwidth normally associated with the antenna pigment peridinin.
For the second set of experiments an attempt to increase green light intensity was made by bundling multiple green LEDs.
This was not successful - bundling did not significantly increase light intensity - and insight on the effects of monochromatic green light on coral host pigmentation remains elusive.