The headers you see are ceramic coated. The coating will last for years if the headers are prepped properly before the coating is applied. Also, headers are usually coated inside and out.
The coating actually does provide some benefits besides looking good. The ceramic coating inside the header reflects heat back into the exhaust gas as it is passing through the header. Hotter exhaust travels faster than cool exhaust. Also, by keeping the heat in the exhaust, the headers radiate less heat into the engine compartment.
Ceramic coating is pretty expensive. If you already have a set, you can have a shop do them. One of the more well known places is Jet Hot. Ceramic coating is pretty expensive and runs about $300 for a set of headers.
Pearl blue & white 69 Camaro with supercharged 350, Tremec TKO, and 3.73 12-bolt
On my old set of headers I sandblasted them down to bare metal, degreased them, and then put on a couple coats of high temp silver coating from Eastwood Co. It cost under $50 all together. Not as good as cermaic coating but a lot cheaper!