I have been keeping sps for a very long time, you can call me an enabler, because I buy these high end acros. Under great water conditions, Acros will color up. whether its under 4500nm or 10k, it will look the same in any tank with the right water conditions. Itll depend on nutirent load, and does not depend on light spectrum. I buy acros, by what they look like under 20k and 4500nm, Im usually not home any way, when the spectrum during the day is around 10-14k, I enjoy it when the spectrum is under the bluer spectrum 20k to all blue. I dont like over saturated acros, but if you have a great photographer taking the pics, white balance is all you need and maybe a light orange or yellow filter, so interpret what the eye can see under the bluer spectrum. Here is a vid, I did under Orphek Atlantik V4 modes 10k full spectrum to Clear blue (4500nm) although under 10k looks ok, but under blue is where the zooxanthellae flex their muscles. I dont think anyone here, goes to the LFS or Frag Swap carry a 5k flashlight or buy a piece in a frag tank, under 10k, youll ask to see it under blues, because thats when youll see the full potential of an Acro.