I def get much better color by focusing on keeping the *major trace elements, like strontium, iodine, and iron. I know strontium isn't technically a trace element, but it is frequently not dosed because many people think that calcium supplements include small amounts of strontium. Anyways I notice better growth with strontium, better polyp extension with iodine, and less stress/rtn/random browning with iron. This of course only matters if your parameters are already pristine, and consistent.
*edit- I only use simple potassium iodide not lugol's for iodine supplementation, I find that lugol's does not provide the same benifits, and I believe this is a frequency issue.