They should be a healthy
pink color, not a muddy brownish
pink color. You also want to watch for him going through the motions of vomiting without producing any vomit. If you see him doing this, put him in the car and head for the nearest vet. If it's during the night, head for the emergency vet. This action could mean that he is bloating, and that because of the large amount of food in it, his stomach has flipped over on itself and has choked off the entrance and exit to the stomach.