Idk I feel lots of the pastels and light woods look bit dead in the game so I tend to just give my sims darker houses with darker woods and darker walls and avoid using ceiling lights in my builds because those often give off way too much light
also you might benefit from some curtains if the outside light seems to wash it all out not sure
+ if you changed your whole apartments lights to white after putting them I'd say try and take out all of those lamps and place them again not changing the color because 1. you can't get their original light color and dimness back otherwise and 2. it could help if all lights are not same color and dimness since that might make lights appear very flatout weird
