J.R.
My girls dont eat when they have colds either. Their Dr. said that it is normal and expected. Not only because they are full of phlem and mucus but normally cant breath either and that makes it hard to breath. He will be fine. If it goes on too long (week or so) then I would worry.
If you think he has a sore throat give him a few teething pellets (Hylands - can find at health food stores or CVS) its not only for teething but coat the throat. I use them myself.
Good luck