given most animals id assume your referring to being white in cold climate covered in snow, their skin is generally not white its black, in this case a bearded dragon is an ectotherm and being white would do it no favors at all (usually the reason cold climate ectotherms are dark pigmented like a red belly as opposed to a mulga) given that avenue of thermal regulation its a strange comment to make on a bearded dragon thread but none the less even endothermic animals would suffer in a snow environment in the case their albino, 1 they would feel the cold more even on a sunny day , 2 generally with albinism their eyes are terribly sensitive and in a glared landscape like the snow fields they would have trouble seeing and along with that would come sunburn from exposure and a lack of melanin