More work-in-progress

I need some advice. Here we have photos of our living room fireplace. The frame in front is something Jake and I made to go around a mirror my friend gave us that will go above the fireplace. However, before I decide whether to actually hang it or "lean it" on the mantle, we need to beef up the mantle. It's something that's bothered me since we first looked at the house. It's a sorry excuse for a mantle on a fireplace this size. So the next picture shows the piece of wood I got last week from an Amish woodworking place...very simple, we're just going to paint it and put it right on top of what we already have.

Here comes the advice part. What color should we paint it? I don't really like the white that's up there now, but it would be easy just to stick with it. We could paint the whole thing dark, but then it wouldn't contrast the trim around the tile work. OR we could stain it similar to all the woodwork in the room, which you can see the color better in the picture of the thermostat and paint chips.

Lastly, I REALLY want to paint this room. You can see, it's a really warm brown right now, which it's not that I don't like the color, but the floors are brown and all the trim is brown and there isn't very good lighting in the room...so it just feels like a dirt cave in there. I'm thinking gray, which you can see in some of the pictures. Thoughts? Suggestions?