Could a dentist replace an discolored filling?

Yes: A dentisti could replace a discolored filling. Better him than an md. But...Keep in mind when you replace a filling you to take away a little more tooth structure and you could end up with a much larger filling that could then lead to a crown or other restoration. Your dentist will let you know.

Most certainly!: If the discolored filling is on one of your front teeth, it's understandable that you'd like it replaced, and it can easily be done by your dentist, that's what they do. If the filling is in one of your back teeth, i would suggest discussing with your dentist if there are other, more pressing reasons (like decay) to replace the filling. If it's only the color, i would leave it alone.

Filling: Yes, if the integrity of the filling is diminished, it should be replaced. Also if the tooth becomes symptomatic.

Yes: Usually after you get your denture it needs adjustment once or twice, see your dentist before it hurts badly.

It Depends: There are many reasons fillings can discolor or seem discolored. If the tooth doesn't show, the filling is sealed &sound, discoloration alone is not really a great reason to replace the filling since each replacement will also reduce some tooth structure. If the filling is leaking or the tooth hurting, or looks very bad then replacement is a good option. Best to talk to your dentist.