What does it mean when an American toad has a very light color?

[Cliygh and Mia 2]

Was the soil a different color? When I first moved my Leopard geckos to a different substrate, they became darker to better camouflage themselves. That could be what's happening to your toad as well, as I think my Fowler's toadlets when they were still alive turned lighter when I first caught them, and turned darker when I moved them to a different set-up