I had a t&a surgery 48 hours ago. since the moment i awoke from anesthesia i have been coughing up thick yellow and yellow/grey mucus. is this normal?

Post anaesthesia : Probably post anaesthesia. As long as you are not bleeding and have no difficulty breathing it should pass. Good Luck

Yes: Debris from tonsillar surgery isn't unusual and along with soreness, loss of taste, bad breath can last days. Persistent bleeding would be a concern. Cool liquids and soft foods are favored for a day or two at least. Your otolaryngologist can advise you further.