I may have thrown a cover over my bike before it had cooled, and my pipe may have looked similar.
I may have thought the blemish was on there way better than it really was, and it may have come off when I brushed it with my thumb one day when the pipe was cool.
My own bluing was exacerbated when I installed the EFI silencer. I didn't mind it from an aesthetics point of view, but I thought something was wrong because of how quickly it bloomed. I did end up getting some of that "Blue Job" stuff, mostly just out of curiosity, and it kind of worked. I didn't get too invested in it because the more I thought about it, the more I realized that I didn't know how it was supposed to work and I didn't want to unknowingly damage something.
My EFI silencer ended up getting a little rusty following an episode where it fell off my bike. Cleaned that up with cola and foil. Looks as clean as the day I bought it.