Typically you want to break paint colors at inside corners. Outside corners can be done, but it is a little harder to do neatly.

I don't really see a break point between the kitchen and DR, but you can easily put another color in the LR.

All colors have lighter and darker shades, so you can pick any color you want and keep it bright. What's your favorite color? Right now, I see fundamentally no color except in the toys, so it's going to be a matter of starting out with something to inspire you and the room, be it a drapery material, a piece of art, a picture of a room you like or anything else (an outfit, a plate, a view...) Spend some time on houzz.com looking at places with open floor plans to see what and how they use color. Once you get an inspiration, the rest becomes a lot easier.

When you say light and airy, but with some color, I think of blues that evoke the sky. My bathrooms walls are painted an aqua blue, paired with white wainscoting and a a beige floor. The combination always makes me think of the beach (sand and sky). My living room is a grayed out version of the same color.

OT, but I am reminded yet again of how poorly my computer renders colors, as Annie's last post of a "pretty green" kitchen is looking full-on blue on my monitor. I've stopped trying to read threads about choosing yellow paints, since they all look pink on my computer. I've tried to figure out how to adjust the color, but it's a laptop and though I've figured out how to adjust brightness, color remains a mystery.

Thank you so much for your ideas. You're right, we have essentially no colour in the rooms at this point. I think I might see if I can find some cushions for the couch or a rug that I like and use the colours from one of those as inspiration for the walls. What do you think of using different shades in the K/DR and LR, and painting the bump out white as a transition between the LR and DR? Also, since I have lighter furniture in the DR and darker in the LR, should I do the opposite for the wall colours?

Using different shades is one way of coordinating the colors, but you want to be careful in the color you choose, e.g., all shades of yellow and it will feel as if you're living in a lemon. If the shades are neutral enough, that certainly can work. If you look at paint swatches from the ben moore color preview, those paint strips are all in shades of the same color. Not all paint makers do that.

I would not paint the bump out white as then that will highlight it and it will become most prominent against the colored background. Rather I'd figure out which way you most often look at it ... I'm suspecting from the DR to the LR...and paint the bump out in the color of the DR wall.

I think using a rug to select the color scheme is a great option too. There seems to be some artwork leaning against the wall in the DR...while I can't see it in the picture, if that's something you really love, it too may be an inspiration for you.

Another suggestion would be to look at the Ben Moore affinity line. Those paint colors are all designed to play nicely together no matter which colors you select.

My neighbor did this in 3 shades of blue and it looks beautiful. She had professional help and it blends so nicely