+1 to this. It looks like the skin is intact but it's about light and water Params. Tri colors usually turn brown upon fragging (most sps take a beating).
Acros are very picky, they require pristine water and good strong lighting. On top of that they don't like changes so the water Params need to be stable.
Tell me a little about your setup and husbandry? Acros can go south in oh 4 seconds once they decide they don't like it.
The tank is just a 20 gallon with AI prime's. Not sure about the current parameters will test them tomorrow. The frag has also been in there less than a week
Ok loghting is good just make sure the intensity isn't cranked all the way. Get a good battery of tests done, salifert kits are good to get.
For now, with a 20g tank a 5g a week water change that uses quality salt, well mixed and at the correct temp will go a long way towards supporting tha acro.