Coral ID and color change

[cbleehk]

Hello

 

i just picked up this piece along with others when there was a sale and didn't really know what it's called. Can someone please ID it for me? I'd like to read about it and find proper care guides. 

 

One say when when lights were out I looked at it and found that the parts that are directly under the lights seem to have a much lighter/brighter shade. (Notice the brown sides on the bottom and the side of that lump where the shade is.) Is this a cause of too much light? It doesn't seem to be worsening but thought maybe I should try other spots.  My guess is that they get less lights thus having increased zooxanthelae and thus the brownish shade. Am I right? 

 

Thanks any appreciate any input!

[Stemcell]

Looks like a mushroom or a ricordea.  And dont think its too much light would close up or shrivel if under stress.