hmm interesting. I have two strips of generic blue LEDs mounted on the underside of my LED fixtures, for the night lights. They turn on with my fuge light, and turn off when the LEDs on the DT turn back on at 8am, so there is always a faint blue even all night.
Tank has been this way since March, and have never seen any negative effects (from what I can tell). Everyone goes into their holes at night to sleep, the saddleback snuggles in her RBTA, and corals get smaller, then expand in the morning.
Maybe it's just me, but it works just great over here. Just my .02.