Morning, it can take a while to get through a thread like this :).
The Xpels are a round (lens-fitting) material that apply directly to the front of the lens. I would say they can be removed if they get damaged or you want a different color. Right now I have yellows on my LEDS, but you can get blue and clear. Mine have some noticeable road-wear and I should be getting some new ones myself, so as to how difficult it is to get them off, someone else can comment, and I would appreciate a good tip on how to start the process myself, lol. Tweezers? :). See link below. I know they USED to have yellow, I hope they still carry it.