I tried BBQ paint on my open primary cover, and even without the heat of exhaust, it turned a brownish color...I could see the difference in sunlight. I wish I could remember the brand so I could tell you not to try that one! Does anyone know of a good brand that wont change color over time?
Well...you could go crazy & have it coated (http://www.jet-hot.com/), but maybe find a local custom auto/cycle shop & see if they have recommendations. Might swing you a cheap fix??? Good luck!