Hi my bearded dragons name is Simmon and he's less than one year old. I really don't know how to start honestly but the reason why Im posting this is because Im Concerned over him. Months ago I've started to see some yellowing around his beard, ear, and bottom base of the tail but I only shrugged it off thinking it was his pigmentation, Of course when I happened to check him again later on I saw that the yellowing grew. I'm worried that he might have yellow fungus. If it is what should I do and what can I do to treat it?
That looks more like shed to me along the vent and along his beard. Keep an eye on those areas and watch for them to become waxy and peel like a shed would. If they become scabby or wounded looking it may be something more serious but it looks like shed to me from those photos.
I agree, it looks more like discoloration, but a sign that usually indicates Yellow Fungus is if it goes away right after the skin is shed, around the vent especially, and then it comes back very quickly. So I'd keep an eye on it and be very vigilant during his next shed. But typically Yellow Fungus looks very rough and almost scabby rather than just patches of discoloration.