I assume by "panels" that you mean your isinglass panels have discolored? We had this happen one time, in preparation for storing I sprayed and wiped our down with Armorall. I rolled them up and put them away in my workshop. A couple months later I unrolled them and found exactly what you described. I know they were fine when I pout them away, they didn't get exceptionally warm or cold so I "assumed" it was silicone or whatever chemicals are in Armorall that caused the damage. I tried cleaning them, tried using a vinyl window treatment, even tied a polishing compound all with no success. In the end I had to take the panels to a shop and have the vinyl windows replaced. It was a lesson learned for sure.