Find out the LRV of the current wall color and use that as a benchmark.

You want to search for colors with a higher number LRV than the current color. LRV is Light Reflectance Value. Can be found on some brand's color chips, but it's listed in the index of all major paint brand's fandecks and atlases.

LRV is different from tone/grayness/muted. LRV is a device measurement. Toned/grayness/muted is a visual assessment. With your specific goal in mind, it would be important to evaluate a color from both perspectives. Look up the measured brightness, LRV, and assess its lightness, tone/grayness.

http://www.benjaminmoore.com/en-us/for-your-home/color-gallery#&ce_vm=0

You can also shop under options by colors and the LRV is on each sample click.

Thank you both!

In addition to changing the paint color - or maybe first because it is easier - you might try putting in additional light sources.

I like to encourage people to try a torchiere lamp that shoots the light up the ceiling. You could put a 65 watt indoor flood light in the fixture; in your case even brighter if possible. I've not done this in a two-story room, but in a 10 foot room, it works great.

And/or maybe track lighting.

Another thought is to embrace the shadows using a darker shade of paint. You might try posting a photo of the room and asking for suggestions. In the house l lived in previous to this one, I had a soft yellow in the living/dining room that faced NE and brown walls in the family room that faced NW. Both turned out well.

This is a photo of a house similar to mine (taken from the loft). I have two windows in the living room opposed to the one. The front door is at the bottom left, and the framing you see on the bottom right goes into the dining room. It's a ridiculous amount of wall space. (The kids ~and their pets~ have moved out so the carpet is coming up and we're putting in a hardwood floor. I want to paint before doing that.)

My dining room and kitchen are yellow gold (think caribbean happy yellow.) And all the trim is white.

Thank you again for all the suggestions. I love a cozy feel, especially with a fire in the fireplace. But the main issue is that it is almost impossible to light the seating areas without using that overhead light (ceiling fan). Which I also hate, but it's a necessary evil since we have to circulate the air.

I see lots of electrical outlets. Overhead lights from fans are IMO the WORST type of lighting.

In a former house with a living room 2/3 the size of that one, I had five lamps. The trick is to put them on timers. In my current house, I have five lamps on timers. I never touch most of my lamps; they come on automatically.

So, you put in a sofa, and behind it you put a sofa table. You put two buffet lamps on the table. Put them on a timer to go on at 4 PM and off at midnight. Every chair gets a side table and a lamp. Put a torchiere to the right of the window and shoot some light up the lowest part of the ceiling with a 100 watt equivalent floodlight. If there are bookcases, you add lights to them. You can get a lot of light into that room; you just need a good lighting plan.

My DR has double windows, but gets very little direct light due to a porch shading the window plus I am surrounded by lots of trees including spruce and pine. For about two hours in the afternoon I get some fairly direct light.

I have Valspar Homestead Resort Sunwash and I absolutely love it in all light. It never looks dull and washed out on dark cloudy days, at dusk, at night with lights on and it doesn't look too bright and gaudy during the time in the afternoon when the sunlight filters in. In web pictures, BM Philadelphia Cream looks similar also.

My room looks similar to the two pictures in the top row (the one with the ceiling fan and the one with the plates on the wall)

Here is a link that might be useful: Homestead Resort Sunwash

Great points graywings! Now I don't feel as worried about choosing the right yellow.

Tuesday, that's a great color.

Looking at my monitor, BM Fun in the Sun 358 might be the ticket. My local Ace Hardware carries BM so I'll stop by there and pick up a sample next week.

Of course, seeing it in person will make a difference. But the LRV is 84.42. :)

Thought I would update with a few photos. Could not be happier with the color. (It's really spectacular in the evening, when just the lamps are on, but I can't capture that in a picture.) It's no longer a cave at night.

View from the 2nd floor. Color isn't correct, the carpet is actually a "seafoam green". Ugh. That's the next thing to be done. Putting in dark hardwood floor. I'd really like a plank floor that I could paint black, and use a cream color area rug.

Last photo. Thanks again for all the opinions.