I bought one about 2 and a half weeks ago. According to the trusted shop I purchased it from they kept it in temps
between 74-77°F. Receiving between 100-150 PAR. They claim it only fed on what was grabbed from the water column.
He said they'd had it for about a year. (Which doesn't seem accurate to me considering the small size.) It's only about the size of a quarter. I am no expert though so I could be wrong.
It arrived on a small piece of live rock which I placed on the sandbed. Underneath a piece of live shelf rock. So it was half shaded, half low light. I also put it next to another piece of base live rock incase it wanted to move it'd be an easier transition.
The next morning it had moved onto that rock, but still under the same conditions. It's tentacles have been extended and colourful. However the center looks milky white and only about half of the red rim directly under the tentacles is visible.
I have twice, (Once a week.) Dusted it with Reef Roids. I'm not sure what if anything it took in as it's mouth is yet to be seen by me. My parameters are stable, and my temp is at a steady 75-75.5°.
Considering it hasn't moved I can only assume the conditions both temp and light wise are sufficient.
Granted my tank is only 6 months cycled. I put a lot of hope into it working out. I know, I know. I'm guilty on that account.
I'll update as/if anything changes. I've seen a few photos and a couple of comments online where the center was white and the mouth wasn't visible. It isn't expelling any Zoo. however. And the owner of the company I bought it from claims that it isn't uncommon.
Though it can't be a positive sign, perhaps it is just how these anems acclimate. Time will tell.