I have a white softopper version that is about 6 years old. Windows yellowed from the California Sun. Softopper said if I mail it back, they keep enough material for them to sew in new sides with new tinted windows that are more UV stable. They would do that for $200.
Like the white. Was debating whether to fix it or just buy a new one and sell the white top as is.
Have a nice rear tinted window on it currently.