I would paint that wall the same as the rest of the room to camouflage the uneven angles. Add some color with Artwork. Let that Art make the focal point not the accent wall color. Depending on the other furnishing in the room, the walls could have more color than a neutral white. I would choose the Art first and use it and the furniture to determine wall color. Also consider the natural light in the room. Strong sunlight can take deeper shades.

Upper wall could match side walls and the lower bookcase section could be a deeper shade from the fireplace tiles. Any color on that wall must coordinate with those accent tiles. Painting the lower wall and bookcases the same shade would unify the space and deeper shade would help blend in those black speakers.

Thank you! I really like your suggestions and reasoning. You cut through all the confusion in our minds! Really grateful you put your talents to work on our dilemma.