I'd like to share one of my hard lessons learned working on my exterior wall project.
When I ordered the new construction vinyl windows, I ordered "white". I asked the sales guy, "are they really white?" and he said, "yes, they're virgin vinyl". I even saw a sample in the distributor's showroom. It looked "white" to me.
But, after I installed the first of the three side-by-side casements, the window did not look "white" when seen with "really white" Dupont flashing over the flanges. And it doesn't look "white" compared with my Azek trim.
The windows were special order, so I couldn't return them, plus, I was out of time, so I had to install them.
But, neither my wife nor I am totally happy with the new windows.
What I should have done was to take a sample of the Azek with me to view it butted up against the display window. There used to be a TV commercial that ran in my area, I think it was for eyeglasses, where the guy says (in a thick accent) "We get too soon old and too late smart!". That's certainly true for me
If it's any consolation, all the products you mentioned will change color slightly after being exposed to weather and sunlight.
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