I have the MikesXS ones on my '83 but I'm pretty sure they're the exact same part. They haven't turned any color really so far, maybe a very slight gold. This surprised me because single wall pipes usually do turn colors. The MAC set I put on my '78 turned blue almost immediately, lol. They are noticeably thinner pipes though. These XS Performance ones are quite a bit thicker by comparison, and that probably explains why they don't discolor as easily or as much. YamahaXS650.com is having a heck of a sale on them at the moment, nearly $40 off. I bought another set for spares.