North facing rooms do well with warmer wall colors to counter the cool light from the north. You could look to the warm ivories and creams if you want to go lighter. Gentle Cream and Navajo White by BM might be worth a try - they both have quite a bit of yellow in them.

I recommend you prime your walls first (you'll have to in order to cover the deep blue. Then find an area rug.T hat will help you nail down your wall color and window dressings. Your area rug needs to be much larger than what you currently have. You should have at least 24" of rug that extends beyond the edge of your table.

Too much oak. Paint the window trim.......Get a much larger , lighter rug. Add light linen curtains..... Light paint colors are usually a fail in rooms with no natural light. The navy paint isn't the problem, the oak, and lack of decoration are the problems.

I recently redecorated a dining room with a northeast exposure and lots of tall trees. AND the east exposure has a covered porch outside. The walls were covered in a dark blue wallpaper and the rug was a very neutral taupe/navy on a dark hardwood floor--it was very dark and dreary. Once the wallpaper came off, the difference was amazing. I painted the entire room--walls, trim and ceiling in Ben Moore Linen White, added a light natural color sisal-look rug, and colorful linen curtains in a robins-egg blue/red/green print. I also recovered the dining room chair seats in a red faux ostrich fabric. It's much more light and airy, the Linen White has quite a bit of yellow which definitely warms up the room.

I wouldnt paint your oak trim. It looks good the way it is, and its maintenance free. Also no paints with yellowy tones. That will not look good with your oak floors and trim. The rug you have is not large enough, and is actually the wrong color for the paint you have. I also do not like the blue up on the tray ceiling. Your room would be brighter if the ceiling and was all white. A lighter shade of blue, or aqua, or even a light green would brighten the room up considerably. I do like your wall art, but, I dont think it is right for your room. Once you have finished painting, look for a nice painting with some color in it. You could also use some accessories and some draperies, even if they are only side panels, that you leave open way to the side. The room, has a very bare feeling right now. It needs to look homey and comfortable to be in.