I see a few dead polyps and the green looks to be algae perhaps?
If it was algae & if it were me, I'd take the risky path & apply a drop of diluted peroxide very carefully to the covered area in such a way that it didn't run into healthy polyps, then rinse after about 30 to 60 seconds. Some others would attempt to smother it with a carefully placed dab of super glue. If it spread, I'd cut off the infected area then dip as a last resort. This carries risks so be sure you think this through.
Does it extend its polyps fully or even partially? If not, that's a bad sign and a repositioning may be in order. These things need just the right flow; neither too little or too much. Polyps should sway back & forth, but not slapping around like little bull whips. Hopefully polyp extension will inhibit further algae growth. GL.
BTW the reds are said to be much hardier than the green Gonis. Especially the ones from ORA. I sure hope that's true as I have 2 & they're not cheap. Had them for 2 months, so far so good. Great extension & they feed. Time will tell.