When I stick out my tongue, it is always at least a bit yellow (if my mouth has been really fry for ages, it is totally coated in yellow bacterial stuff). I don't think I have a major problem with oral hygiene, but I'm wondering what a healthy tongue should look like when stuck out. Should it basically be pink all the way up, or is it normal to have some yellow coating?
A tongue may have this appearance due to build up of dead cells on the surface. And then it's worse after not being used as there is no friction from food removing dead cells that might be trapped between the papillae. Some tooth brushes have another side that can be used to brush the tongue to remove these cells.