My understanding after having a similar conversation in my local club, was that the blue spectrum provides better light that the corals use. The white lighting is more beneficial to plants/algae. LEDs changed how we think about light. It used to be the opposite with MH you wanted the yellower white lights for growth and the blues were for the appearance of the tank. But the wavelengths of the lights that were toward the yellower end still contained a ton of blue which the coral used for growth. At least that's how I took it from the conversation we'd had. But I'm a simpleton, so take that for what it's worth!
Later,
Brian