One other thing—the paleness could be explained with one, tiny note. "Melanin production shuts down after the transformation." It's no longer necessary to protect yourself from the sun, and extremely pale coloration could allow crepuscular vitamin D synthesis (i.e. getting your sun from the brief, dim light at dawn and dusk)

Idea shamelessly stolen from herpetology, and the different UV needs of diurnal and nocturnal lizards.