Moidol, the whole trick to getting great color is a nutrient balancing act.
Not all corals respond the same and tinkering with nutrient levels that are either too high or too low can put you in danger of killing everything. So many variables your head will spin
I choose to play it safe lately and keep a very low nutrient level. My colors are lighter that I would like but the corals grow faster, and IME (in the type of environment) the survival rate on my acros is awesome.