[pogodzib]

Before I tell you what I think the brown ones are, do they shrink up to near nothing and suck back into the rock when disturbed or do they just close up but remain outside of the rock crevices. Also, could you get a close up shot of the polyps?

The green one is Green Star Polyps. A very easy coral to keep that many beginners start out with. They can spread quickly and overtake a tank if not controlled.