notebook skins for discoloring of palmrest

[Wills]

My notebook's palmrest is discoloring. I called dell and they are sending a technician on site to replace the palmrest.

What I am curious about is whether or not the onsite guys are actually dell employees with experience on XPS or if its like a 3rd party company who can potential screw things up more from lack of experience.

the other question is does anyone know or recommend skins or something I can put on the palm rest to prevent discoloration again in the future?