tad-poles

Can someone tell me why my finger turned from brown to greenish? I know its not my eyes. Also, can i get the scientific name for this one? Its kinda difficult to tell I'm new at this. And, living conditions please. TIA Need scientific name for this as well, and I have no idea why it suddenly shrank in size. I mean, one day it was opened up and had polyps, the next day it became like this... Can someone please shed some light on my predicament? Sorry but i don't have a before picture... TIA I'm a newbie thus seek opinion and answers from more experienced individuals/hobbyists THANKS..