This is clearly an over simplification. when you are considering the benefits of blue light I first start thing off by think where the coral comes from. IE depth of water because as you go deeper in the ocean you find that the water Colum filters out the larger wave spectrums and interns the smaller blue light spectrums are left. That being said the depth of water the coral is in matters a great deal because to how it reacts to the lighting.
I remember circa 2008-10ish many ppl saying on ReefCentral that the blue spectrum 400nm to 500nm was "for our eyes only" and did lil to nothing for corals
Of course, 12-14k Metal Halides rules the day back then