My oem pipe is badly blued around the oxygen sensor, and there is a yellow circle around the silencer itself, about an inch wide. Probably where a baffle, or the cat con itself is welded inside, causing a hot spot. I don't mind discolored pipes, they are one of the things I liked about my old Triumph. It was a bike made to be ridden, not cleaned and polished (well at least it was back then) So blue pipes and oil and grease on the engine did not look out of place.
Glad to here the EFI pipe does not have a cat in it. If I get it, I will keep the oem pipe at least until the warranty runs out. There are no inspections in AZ, and most bikes here have aftermarket pipes. I might be able to get a couple hundred $$ out of the stock pipe on eBay. I know one person that paid $500 for a new stock Honda Rebel 450 exhaust system on eBay, and was very happy to get it. It was the last thing he needed to finish restoring his bike.