Longevity of dark finishes on vinyl and fiberglass windows
We're getting ready to begin replacing windows in our 1939 home. However, the first two windows we'll replace are south-facing with little mid-day shade One is a 10' bow (1950s vintage) and a 10' casement (1980s vintage). I'm looking at either fiberglass or high quality vinyl windows. I'm assuming we'll be here another 10-20 years.
It seems that our color preference might be the deciding factor. The house is red brick with a fairly dark blue color for the trim. We wanted to keep the trim color dark and would be happy with the "Forest Green" that's available for some windows except for the fact that there may be fade problems. I've read that the dark vinyl can be buffed and restored to a great degree. I've also read that one company's (was it Andersen?) "Forest Green" on their aluminum clad replacement windows can NEVER be painted. This was a year or more ago that I read this and saw references to AAMA specs.
I've read the comments in other threads about the Soft-Lite foil laminate, but don't know how that compares to the alternatives.
Are there industry specs for vinyl and fiberglass exterior color fading? Which, if any, of today's available dark finishes have been around long enough to gauge how well they'll hold up longer-term?