all the same color

Same color. do not cut the room in half..................

For me it would depend on the room. In a den or a game room I would go with color to add some of my personality to the room. If it's a bedroom I would tone it down. I got to confess - I have a bright lemon yellow (top) and deep navy (bottom) game room with that same ledge around two of the walls in my basement.

In this room the ceiling looks very low... the horizontal lines add to that ...if you do anything ...a vertical siding applied to the top half may even out the wall a little and add a visual that will lessen the look of the low ceiling....same color upper and lower ....will be most effective in whatever you do for the same reasons