When it comes to lighting I know that the spectrum of light that is produced from each light source is different which causes different visual effects. There are certain spectrums of light that bring out reds in a very special way. Off the top of my head I don't remember how the spectrums are rated in kelvin but there is science behind lighting that is for sure. In terms of LED use I agree 100% with you that pearls shimmer more under LED's. in fact if you want your flowerhorn's pearls to really shine use a combination of blue and white LEDs. When just the blue antic lights are on the pearls look like a glowing blue electric light show. I love turning just the blues on at night, its creates such an ambiance in the room, and my fish look like they are a part of a black light show. I have a fluorescent fixture that sits behind my LED fixture. When the fluorescent light is on by its self I see deeper reds on my fish and my tank takes on more of a relaxed pond feel. When I turn the LED lights on they are so powerful that the fluorescent fixture light just disappears. You literally can't tell when its on or off when its on next to the LEDs. I do know that LEDs come in different power strengths and mine is really powerful. The LED fixture I have was designed to support marine corral life.....lol....so I'm sure that is the main reason my fluorescent light gets wiped out by the LEDs.