Hi,
Thanks so much for your questions, and the photos. I love your house -- it's very Southern California! The wall color you have now looks great, but I understand wanting a change. A subtle blue would look great with the wood flooring and nice white trim. It's possible that you could leave one of your walls as painted in the rich brown, for your accent wall, or choose another deep brown. Be sure to sample the colors as lighting and flooring can affect how a color appears once it's in the space, as well as differences between computer monitor color rendering.

Here are a few similar blues to consider:

Benjamin Moore Seacliff Heights http://www.myperfectcolor.com/en/color/5631_Benjamin-Moore-688-Seacliff-Heights

Benjamin Moore Heavenly Blue http://www.myperfectcolor.com/en/color/89_Benjamin-Moore-709-Heavenly-Blue

Benjamin Moore Bali http://www.myperfectcolor.com/en/color/5643_Benjamin-Moore-702-Bali

For your exterior, here are suggestions to sample in light green. Once you choose your exterior color, you can sample trim and accent colors. It's also important to sample exterior paint, as it can appear brighter on large surfaces.

Benjamin Moore Chameleon http://www.myperfectcolor.com/en/color/5472_Benjamin-Moore-526-Chameleon

Benjamin Moore Country Green http://www.myperfectcolor.com/en/color/5486_Benjamin-Moore-540-Country-Green

Benjamin Moore Soothing Green http://www.myperfectcolor.com/en/color/5481_Benjamin-Moore-535-Soothing-Green

Benjamin Moore Warren Acres http://www.myperfectcolor.com/en/color/5473_Benjamin-Moore-527-Warren-Acres

I hope these ideas are helpful,
Diana

Thanks Diana, these were very helpful!
Greg