If skins would not apply to collectibles, it would encourage players to use them more. Some skins make (almost) impossible to find certain collectibles. And Walpurgis Night buff is just silly, 5 mins in 2 days is simply not enough. It would make sense if it lasts until current collect quest expires. I usually don't even search for collectibles, because there is only two choices: pixelhunting or cheating (which i can't use ;D )