I have a home office that I created using soft yellow-greens (walls and carpet) and aqua blues (upholstered furniture), with cottage white furniture and some natural accents. The problem is that the room is on the north side of the house so doesn't get a lot of natural light so feels dark, cold and rather 'swampy' with the mossy green walls and carpet. It's not inviting and needs some energy! I don't know what to do to warm it up. I'm afraid of introducing a strong accent color (like orange or yellow) for fear the beachy feel will get lost (will it?), but everything is in the mid-tones so it all seems so monotone and lacking contrast. Any advice on a color accent to introduce or or a wall color that might help?

Coral is very beach appropriate - not quite orange or yellow, so I don't think you'd lose your vibe. If you don't want coral accents, a poster with coral tones with a large white mat and frame might break up the green walls and add the punch you're looking for.

Great suggestion! I do love coral... thank you!

Consider trying different sources for lighting before switching up the colors. The type of indoor lighting used can make a marked difference in brightness and ambiance.

Great suggestions.