I've seen a ceramic coated plenum from about 10 years ago. I remember the appearance was sort of like it was coated with a pearlescent material. It wasn't completely clear and gave it some odd colors in different lighting. I don't know anything specific about the type of coating that was applied besides it was for thermal reasons first, cosmetic second.
Later
"If A equals success, then the formula is: A = X + Y + Z, X is work. Y is play. Z is keep your mouth shut." - Albert Einstein
When was the last time you *really* did something with your Z to call yourself a Z enthusiast?
