Any of those colors are pretty normal. The milky white/milky yellow pee is due to the pigs body getting rid of extra calcium. Also when pee dries, as it comes in contact with the oxygen in the air it can turn a reddish brown/brown color. If you notice dry white spots you need to run your finger across them and feel if it feels smooth or gritty. Grit in the white spots can mean bladder sludge and that can be a leading cause of bladder stones. Any pee that is constantly milky means they could be getting way too much calcium and that certain foods need to be cut back on like parsley, baby carrot, spinach and kale.