Question about jetting and pipe color?

[CGCinc]

I just got back from a hard 3 hour ride today and noticed the header pipe where it comes out of the head was a deep redish tint with just a few bluish spots. The bike runs very good with no hesitation or flat spots and I had it wide open in high gear today for a few 30 second jots...

I'm wondering if that is a normal color?

its a KFX 400 with Yoshimura Comp 3 full exhuast, k & N filter with the top of the air box off and a 150 main jet.....I'm going now to check the spark plug and maybe change the jet to a 155

Lean maybe.

Check the plug. If its tan jettings good. If its kind of white its lean. A new plug will give the best reading. Could also do a plug chop.

[CGCinc]

The plug looked fine but I jumped up to a 155 jet.... it doesn't feel like the top end is as strong as with the 150 jet but it still runs perfect, no stumble or anything...