There are several brands of heat resistant paints and stains for a wall gas fireplace. You can purchase them from your local hardware or discount store. You don't have to rely on the ages old stove black or barbecue grill paint of days past and can perk up your room with a bright color.
Krylon is a spray paint that is readily available and popular. This brand provides spray paint for just about any surface from metal, to wood or plastic. They also have a heat resistant paint that is made specifically for fireplaces and grills. This paint is available at any store that carries a wide range of Krylon products.
For years this was used to paint cast iron stoves back to their original black iron color. It is also popular for painting wrought iron fences and trim because it is durable. This paint is available at any paint or hardware stores.
Barbecue Grill Paint
Since barbecue grills not only have to endure high heat and fluctuations in heat, they often have to withstand elements. Grill paint can also be used for wall gas fireplaces. This paint is available in several colors and is available at most large home improvement centers.