Morr,
I would suggest clicking the "chat now" button above and asking a live rep. "Sandstone" to me sounds like the beige color. The 2 uploaded pictures and REI's listing of the product would concur. However, Petzl's website lists it in the same confusing fashion. If you ask a rep nicely during regular business hours, they can have someone in the warehouse check for you!
I hope this helps a little.