My 9 year old son's skin color is yellow then his age fellows..please guide?

Physician visit: If this is new, an office visit to rule out jaundice (or less likely kidney failure) is in order, unless junior's lately taken to eating a lot of yellow vegetables (one big carrot / day will do this; yellows palms & soles). Some folks run a higher level than others of the protein that carries carotene from the diet in the blood.