A fact I was thankful for when it came time to lug it outside to spray it with grey auto body primer.
After priming it I dry brushed several acrylic colors over the entire wall to make the stone texture stand out. Next I mixed up a thinned down mixture of acrylic paints to make a wash. Using a soft brush I applied this over the stone and wiped off the excess with a rag. The wash settled in the cracks and crevices giving an antiquated look to the wall.