Button Polyps make a nice addition to your reef, and there are different kinds. These are Palythoa, which are recognized by the mat that these individual polyp heads extend from. When touched, they slime like crazy, so avoid doing so if possible. Palytoxin is considered dangerous to humans, so avoid touching your mouth & eyes; wash your hands after handling. Eye protection is wise, as the polyps may squirt fluids when fragged. I've had no problems personally, and shared numerous frags of this coral in the past year. These look brown under normal lighting, and green under blue lighting.