Yes. Do it all the time.
A brown acro usually means high nutrients (phosphates/nitrates) so you should start by brining those levels down SLOWLY!
Once your PO4 and NO3 levels are low or undetectable, you should see a massive improvement. If it does not color up, I would suspect your lighting to be the issue.
If you determine that its a blue acro and you want it to be more blue, you will need to test for iodide and bring up the level to 0.03-0.04.
If you determine that its a red/pink acro and you want it to be more red you will need to test for potassium and bring up the level to 400.
Iron is what you will need to dose to get green but make sure you don't overdose because then your yellow corals will have a green shimmer.
In an SPS dominated tank, you will need to dose these trace elements to maintain natural seawater levels. 10-20% water changes wont keep up with demand and even high end salts like Tropic Marin Pro Reef have very low levels from my experience.