Hi. I've tried out a chocolate brown on your walls. The effect would be to darken the room considerably, of course, but I love the rich effect it gives in the first picture below. I found something really interesting, which is that on the other side of the room, to have that dark a colour right next to the brick made it pop altogether too much. But when I lightened the colour on that wall to something like the same colour weight of the brick, it looked better. So I did that in the second picture below, just on those bits of wall, as well as messed a bit with the mantle to show that a few large items/groups draw much more attention to themselves and therefore away from the expanse of brick. (Sorry, the brick got a bit wobbly.) The row of small items doesn't do that at all. So I recommend clearing that mantle of most of its bits and pieces and also moving that little chess table somewhere else -- tucked in next to the two-seater?