NO, that's not normal. Did you take it from a dim store tank (brown) and put it under brighter lights at home? You might have bleached it...
Try putting it on the bottom of your tank where it will get a little less light and see if it comes back... if it bleached bad it could take a while.
As long as it doesn't smell of death I'd give it a chance to recover.
This is how mine looks, both in the store and when I got it home:
http://www.zooxanthellae.com
Green Bird's Nest, Seriatopora caliendrum
It has been in my tank 3 days now and still looks great.