A question I get from clients all the time is “will a dark color on my walls make my room feel smaller.”
The short answer is, maybe.
Ultimately, in a room with little to no natural light, dark walls may actually make your room look BIGGER. Think powder bathrooms or small office space. If you use the wrong color in the wrong room, sometimes even an all-white room can feel small.
There are tricks to using darker colors in a way that works (north-facing rooms tend to do better with darker colors) and if the trim is painted a starkly contrasting color it could draw your attention to the contrast and make the room feel even smaller. But, if you can use color in a way to reflect light, you can play up your existing space and highlight and the height and depth of your rooms.
Grounding darker paint colors with neutral staples (like a big, creamy white couch) and lighter decor can help create a sense of depth and grandness, which is why, when dark walls are done correctly, they make such a perfect statement.