I've run my Sceptre Pipes from the day I got them like 4 years ago and they still look like new.
No dis-coloration anywhere.
Check the ingredients of any cleaner you use on Stainless Steel.
If it has Hydrochloric or Muratic Acids listed?
That's a No-No!
It will cause corrosion.
They may be fine for Chrome but not Stainless Steel!
Also don't use a fine steel wool type product to buff the Pipes.
That embeds crap on a microscopic scale that causes problems also.