Bella is definitely a beautiful male! You are partially correct, mature males of most mutations have royal blue ceres when mature. However, immature males (but not immature females) have shiny pink or purplish ceres with no hint of white which normally turn blue, except in cases of recessive pied, dark eyed clear, and albino/lutino budgies. Budgie males of these mutations keep their immature pink cere color their whole life (females of all mutations have pale whitish, chalky pinkish, pale blue, or pale beige ceres with a matte finish and a flattish appearance when immature and when in condition the ceres are brown, as you probably already know).
Belle looks to be very heavily pied (I'd say combination pied, which is recessive pied in addition to another pied mutation) from the photos, which would give him the pink cere his whole life. He's actually so heavily pied that I suspected dark eyed clear at first but he does have some patches of black feathers.. do you have other photos of him?
Since he's used to his name I really don't think you need to change it~ or if it really bothers you, you could always call him "Bello" since that means "handsome/gorgeous" in Spanish~