Old school was pipes turn blue cause you ride the bike. They turn right at the location you describe. It is where the exhaust gas is hottest. Nowadays, they put decorative heat shields on most pipes, maybe yours doesn't have them. I never had much luck deblueing my old pipes, but I have yet to see my heat shields blue. But I do notice that aftermarket exhausts warranties have disclaimers. Burning lean makes the exhaust hotter, hence blues the pipes. So maybe a fuel controller might help. It would be interesting to know, who did make the pipes?