Yes, with two chestnut parents (and no sign of greying on them), your colt is guaranteed chestnut. All chestnut (not greying) foals will have pink skin around their nose/muzzle and genitals, that goes away in a week or so. Splash is the most common trait that causes a blue eye, but Sabino can too. Any time you have a wide blaze a blue eye is possible. He is lovely. Congrats.