White filling stained and turning grey, would it be straightforward to just get this filling redone? (Photos)

About 2 years ago, I had to get a white filling done in between 2 of my front teeth and it wasn’t done particularly well - you could easily see where the filling started and the tooth ended. Now, it seems like this area is stained/turning a light grey color. Would it be straightforward to just get this filling redone?