I got a cool coral the other day. It's ok for beginners (like me). It's a bubble coral. It blows up these individual sacs during the day. It likes moderate lighting and flow. It's photosynthetic, but will also extend tentacles at night and I've given it combo of Cyclopeeze and mysis twice. Over past couple days, it's looking much happier, first couple days few of the sacs weren't inflated, but he seems to like the new spot I put him. Only feed him ever 2-3 days. Here's a pic
Mines yellow, but there's also white, green and I've seen a kinda pinkish color too.