There is a lot of info online about the best spectrum for your aquarium based on what you have in it. After a lot of reading you will have a better idea of what you need for coral growth.
Another way of seeing this topic will be "how you want your tank looks" independently on what would be the best balance for the corals.
For example. Corals growth great in MH. But I never saw the colors that some LEDs, are able to pop out based on what side of the spectrum you have them setup.
At the end, most corals will adapt and will growth if they have, in a certain balance, a full spectrum.
More blues or less blue will shift the spectrum to one side or the other, but the mix of both (blues+white) will make your corals growth because they have all what they need.
In particular, I hate blue tanks, as they look very unnatural. But that is me !!!
In my 6 T5 light fixture I have 2 blue actinic- left side of spectrum), 1 pink (right of the spectrum) and 3 that covers all of them (White-bluish).
Cheers