No to an accent wall. Add color with art. Black for the fireplace.

Personally I do not like black fireplaces, especially in stark contrast to white. I would paint the wall and then determine a color for the fireplace.

Black wall, then decide fireplace

okay update! painted the walls white and the wall black... still on the fence about the fireplace?

Will you be adding curtains to the window? I think the fireplace in white looks fine the way it is. If it’s in black I think it’ll “jump”’out too much because of the tv above it. Add a piece of art work with some black in it on the wall by the window.