Well he's probably got a really good sense of smell, innit
So he'd know.
( Captain Wow currently being a cunt in Infamous, Fri 21 Dec 2007, 11:32, archived)

He could probably smell that it was blue

( Professor Kenny Martin Receiver of the world's first Marbleositing, Fri 21 Dec 2007, 11:34, archived)

And his size.

( Captain Wow currently being a cunt in Infamous, Fri 21 Dec 2007, 11:35, archived)