I have some live rock rubble in my tank and there is a golf ball sized piece that appears to have been a pinnaple coral or a clozed brain coral. I have had it for a little over a month and it was brown untill today I now I see that there are many neon green spots on it. Is this some type of algae? It appears as though the coral is returning from the dead but I don't think thats possible. Does anyone know what this lime green could be coming from?