These fake stone panels were purchased from Menards. These are Rocky Mountain Novistonefs by Novik (novik.com). The panel on the left is as is. I thought it bland and unrealistic. The panel on the right is the same stuff but I dry brushed craft paint onto each stone to create a varied, more believable looking stone finish. To follow is complete instructions on how I accomplished this task.
To transform the fake stone panels into authentic looking stone you will need: 5 Stoney looking colors of craft paint. I used Bleached Sand, Sandstone, Linen, Fawn, Barnwood. Use what appeals to you but subtle earthy colors work best. I also wanted the stone to be light colors. You may want to match the colors to your project. You will also need 5 disposable cups, a 1" craft brush and matte sealer.
Here is a section that has been dry brushed with the various craft paints. There are two major reasons craft paint was used and not professional paint. Craft paint contains less pigment and goes on more sheer to begin with. Only a hint of color is all that is wanted when creating a dry brush effect. Craft paint is inexpensive. A small bottle of craft paint is less than $2.