Architecturally, is it part of the wall or part of the ceiling? It's really huge. You may have to try both colors and see what helps to make it disappear the most.

Since paint isn't a permanent home improvement, you may have to experiment.

I would paint all three sides a wall color.

The hanging light will look much better without a white ceiling paint background. IMO.

sambah006...it is carrying the load of the upstairs. The outside wall is from each side, and the space behind is just a little bump-out

I vote for wall color! Using this mantra from my design 101 class...Light colors advance, dark colors recede!