What stock is that? Or maybe the better question is, what's on the stock?
That's a Desert Tan Hogue Overmolded AR-15 Stock.
http://www.hoguestore.com/index.php?main_page=product_info&products_id=8194
All of them:
http://www.hoguestore.com/index.php?main_page=index&cPath=16_679_833
Hogue has only been selling them for a month or so now.
They claim it's on back-order, but I ordered one anyway. It came to me a few days later