Plot twist: Original frag was purchased 1963 right after the Kennedy assassination and just now is coming around...
I kid I kid
On a serious note, I have had frags that have lost color and gone pale but bounce back in a week when I correct the problems but brown frags have sometimes taken 1-2 years to regain color. I inherited some corals when I first started keeping SPS from a guy who traded them in for a tank I was selling. They were ***** brown and had NO color, I stuck them on the rock work facing my back wall and figured i'd leave them be and see what happens. A year later I ended up moving them to the front of my tank and some ended up being the nicest pieces I had. It just took a very very very long time.
Keep in mind! Theres a whole slew of species that, you can litterally move them an inch, and theyll brown out. Like a strawberry shortcake/microlados or the vivid rainbow that i can accidently overfeed for a week and itll brown out- for example. For my experience, took a couple months to get their color and full pe back.
I have a Hawkins Echinata that came in ok color but browned out in my tank within 3 weeks .Now it's over a month and still brown .
Performed ICP testing -no alarms except for AL due to marinepure may be , measured PAR and around 250 on the Echinata .. ALK -8 ,Phosphates- 0.06 and nitrates - 10 .