With a northern exposure I would say you need a warm white. Many paint mfrs make a warm white called Swiss coffee. You could start there! To the naked eye it will appear pure white.

We recently painted our master, which also faces north and the only light shaded by covered porches. We chose a cream called "Patience" from SW. I tried it in a south/west facing room and it looked pure white! But in our bedroom it's very rich. As you seem to be aware, light changes everything, doesn't it?

Designers often say attempting to lighten a dark room with light colored paint is not effective. Light shades in a room with little light leave it cold. Instead, going with a dark shade will give the space a warm, cozy feel. Check out the post " neutrals, neutrals" and look at trailrunners warm chocolate walls with white woodwork. Love it.

Art teacher, this sounds pretty! I'd love to see a pic please.
Thanks!

I personally would not go white at all... so I'm no help! LOL!

Our living room has a northern exposure. When we moved in the whole house had been painted a warm white by the builder (spec house, we were not a part of the process in any way). Despite the warmer white, the living room always felt grey and cold, even on the sunniest of days.

Some years back it acquired one rich warm red accent wall and the rest of the wall space became a warm coffee-with-cream. What a difference.

White walls won't necessarily make the space seem bright. I would go for some color, even a soft one. But if you are determined to do white, then for sure head for something warmer.

Depends on what type of white that you want. If you want a crisp white w/ no undertones of any color but is still rich, bright and vibrant w/o being cold I'd highly recommend SW High Reflectance White. The paint guy described it as pure white w/ extra 'oomph'. I recommend viewing the chip on the SW white collection handout. You can see how it stands out amongst all of the other whites. SW HRF is typically used as a base to add other tints to. Since there are no tints this color picks up and reflects back large blocks of other colors quite easily. I hated it in my hallway where it turned pink becuase of my stained glass window. I love it in my office becuase there are no other outside color influences - just blues in the form of flowers and pillows.

Here it is in my office. I chose it for this room becuase I wanted the wall color to stand out and hold it's own combined w/ all of the black and white.:

Here is SW Pure White in my LR at one point which has a NE exposure and low light. I had a hard time getting the right white becuase of all of the green foliage outside of the window. This was just a very soft white w/ no yellow or creamy tones. Really liked it a lot! Please don't judge me on the sad silk floral whatever in the vases - I was just trying to visually figure something out!:

thanks everyone for your thoughts. Believe it or not, I'm a fool for color. Tobi Fairley is one of my favorite designers and I know that white isn't the cure all for a dark room. My LR is turquoise and my kitchen is apple green so as you can see, I'm not afraid of color. That said, my hubby has a vintage globe collection and framed vintage maps that are colorful...so like ttod's office we want white walls so the art, globes and red built in desk will be the focus. Trust me, there will be no other white walls in my house. ha.

ttodd, thanks very much for your detailed info and photos. I LOVE Your office. I also think the white you described will work well since there are no undertones. White can be hard to work with due to undertones. That's for sure. I'm going to give it a whirl. Thanks again.