Sorry, I blew up the photo and noticed these are Akrapovic muffers
Some manufacturers offered muffers with this color pattern, such as Micron, Ladybird, etc., but not Akrapovic to my knowledge.
What does the right muffler look like? Is it similar or not?
Titanium doesn't discolor like this unless it's heated quite a bit.
If the muffler packing has not been replaced in quite some time, the exhaust gasses could be blowing onto the sleeve causing discoloration.
If the right muffler looks normal, then you might need to check and repack the left muffler, or both to be sure.
Last edited by SubSailor; 12-21-2011 at 10:16 PM.