I am a certified thermographer. Certified by FLIR, the maker of infrared cameras used by fire depts., the military, police depts., news helicopters, various industries. Infrared is a form of electromagnetic radiation used to measure temperature. The color FLIR camera I used troubleshooting locomotive problems was $30000 5 years ago. Infrared theory states a good receptor is a good emittor. In other words, a color that easily absorbs infrared (heat) also readily gives off infrared (heat). The best receptor/emittor is flat black. Hmmmmmm..... also the most common color of a smoker or grill! Now. We hear of people insulating their smokers to keep heat in. Their BLACK smokers. And that is OK, it works. But if your smoker were painted SILVER then infrared theory comes back into play! You see silver is an extremely poor receptor/emittor. Therefore infrared (heat) would be reflected back into your smoker , not allowed to escape. Not all infrared, but a good portion of it. The exhaust manifolds on Diesel locomotive engines are painted silver because it holds more heat inside the manifold. That heat is what drives the impellor of the turbocharger that forces fresh air into the cylinders. The more heat retained in the manifold, the more efficent the turbocharger and the engine is. The best color for heat retention is silver. I can easily prove this using my RayTek digital infrared thermometer. I will play with it and take some pics to post. OK, the can of worms is open - go for it!