Welcome to R2R! Not sure how to best answer your question but corals use energy best when it's presented in certain key wavelengths. As a general rule, reef lighting is tuned to use these wavelengths in the right proportions to feed the corals without using too much energy outside of those wavelengths since it's just wasted energy and usually promotes growth of other things besides coral. Here is a video that should give you a pretty good idea. And some of it is preference. Some people like to see more blue and some people like their reef to be colored a little more naturally.