Toni Morrison is an expert at writing beautiful narration. Beloved is told in third person omniscient, but also from a switching third person limited perspective. The narration switches between the points of views of many different characters in the novel, and as it switches it often adopts that character's tone of voice.
The most obvious example of the narration adopting a character's voice is when the narrator switches to Schoolteacher's point of view when he comes to kidnap Sethe. Suddenly the narrator is calling the colored people slurs, talking about Sethe as if she's an animal, and using the n-word in nearly every sentence.
When the narration switches to Paul D's perspective, the language becomes harsher and sharper. When it goes to Denver's point of view, it becomes more emotional and immature.
Toni Morrison uses this third person limited switch very carefully. We'll often begin by learning about a character (like Baby Suggs, for instance) through another character's point of view, and after a while the narration will go to that character's train of thought and we'll get some really interesting insight into that character.