I have stainless side pipes and mine have never turned blue. The do quickly gain a bronze tint to them. At first it kind of bugged me but now I like it for some reason. I can get rid of the bronze tint with a quick polish but it immediately comes back the next time I take it out on a road trip.
Other than the bronzing, they hold up quite well. No cracks or scratches or the like and this is after 6 years and about 25,000 miles.
Here's a view of mine so you can get an idea of the bronze coloring.
Chris