Thank you for all your comments so far, I am finding them very helpful.
I took some photos last night to clarify my problem.
Let's start with my diagram.
I wanted to give you an idea of the layout of the rest of the condo. The fireplace area is our "living room" - this is where our couch, tv and coffee table are. The other half of the room is where our dining room table and chairs are. That area flows into the kitchen. The hallway highlighted in pink (painted light green) leads to our bathroom and bedroom. The den is off the kitchen and will remain unpainted as Shawn has told me, in no uncertain terms, not to mess with Manland.
Right. So. Moving on.
This is the reason I had not attempted to paint the wall. Don't ask me what all those plugs and wires are for. I don't know what they're for, I just know they're all necessary to run Shawn's System (which totally deserves to be capitalized and when said out loud, should be said in an awestruck tone of voice.)
I could not take an accurate picture of the shades of green because I had no natural light, so imagine these greens but less yellow.
These are walls A, B and C. Sorry for the poor picture quality. I have no excuses.
Honestly, I'm very hesitant to paint C (the white surrounding the fireplace.) That being said, I think it might look silly if I paint B (wall behind the fireplace) and leave the fireplace white. Also, I feel like A need to be painted the lighter colour to create division in the room ("dining room" would be olive green, "living room" would be light green.)
I have no idea what to do but I can't leave it the way it is. Right now it looks like we ran out of paint before finishing the job.