Okay. I painted all three walls a light gray. It looks white in this photo, but it's pretty much the color of unpainted drywall. After that dried, I mixed some black and paynes gray into the light gray base until it looked like slate. Using a small brush I painted the rock faces. As you can see it still looks very flat. I will go back and drybrush a medium gray, and then a light gray on top of that for the highlights. This is what will create the depth. Lastly I will create shadow with the airbrush. More to come next week!