We had a very similar experience to a previous post, but the responses haven't helped us solve the problem. This is the original post info: "We bought a brand new dryer two weeks ago and found a blue film on the inside that won't come off. It wasn't there before. This is the reason we bought a new one because the old one had developed the same stain. It would then transfer to all light colored clothing that we dried. There haven't been any pens, colors, crayons, etc. washed and no new dark blue items. Any ideas what could be causing this?"
Other than the responses in the Archives the only thing I can think of is asking the manufacturer of your dryer. I also must mention that unless this stain is discoloring clothing I truly don't understand why it would matter.