The pipe turning colors is related to the temperature of the exhaust.  Colors start out as straw colored....and as the exhaust gets hotter it turns golden and then blue.  Lean/rich mixtures can affect the color, as can riding styles and ambient humidity and temperatures.  The bluest Savage pipe I have ever seen was on a bike with only about 100 miles on it....the owner liked to let the bike idle and warm up for a long period of time before riding.

Letting any kind of wax or oil or cleaning product get on the pipe while it is hot can have a big effect on the color.  The chrome should be clean....and Blue Job is the only thing that should be used on the exhaust chrome to clean it.

Pipe discoloration advances from yellow to brown to blue to purple to near black.

When I stuck an the Emgo shorty megaphone (same thing RYCA uses) on my 2001, my pipe started turning noticeably yellow with just 30 miles of riding.  I also had indications of running lean (acceleration was a little flat). I upped the main jet (forget the size, but it was the next step up) and did the carb needle spacer mod. That stopped the discoloration, if fact the yellow cleared up.  The bike ran way better.  

After getting tired of that loud Emgo, I replaced it with a Dyna with a 1/2 inch hole drilled in the baffle plate for a little extra noise.  I left the jetting alone, so I think it might have been slightly rich. It ran great at all speeds with no deceleration after-fire gunshots.  It did have a nice burble as it neared idle rpm and there was only an occasional soft poof on shutdown.  Great power and excellent throttle response. I generally didn't need to choke (enrich) to start until the temperatures were down in the 50's.  I had no pipe discoloration.  However, I would only get about 48 mpg. I considered that a small price for how well it ran.

It's strictly a cosmetic problem... there's nothing wrong with the bike...

My pipe is blue/black from head nearly to muffler...
Me likey!... ...

GRRR!,..ARGHHH!... ...