Meaning of "fit in with something" in Essential American English Dictionary

fit in with something

phrasal verb with fit us /fɪt/ verb (present participle fitting, past tense and past participle fitted)

If one thing fits in with another thing, they look pleasant together or are suitable for each other:

It’s a very nice couch, but it doesn’t fit in with the rest of the room.

(Definition of “fit in with something” from the Webster's Essential Mini Dictionary © Cambridge University Press)