Does Apple’s clear case with MagSafe turn yellow over time?

My wife has had the iPhone MagSafe clear case installed on her Gold 12 Pro Max since December 2020, and after over 3.5 years, I was surprised by what happened to the transparency of the case. 

The edges of the case have purple fringing, but the back of the case is still perfectly clear. No yellowing in sight.

What I think is happening here is that during the manufacturing process, the parts of plastic that had to be heated up and bent upwards to make the sides are more "aged" due to the heating, and develop that purple fringing over time. Since the back of the phone is flat and the flow of plastic is uninterrupted, it keeps its clear color. 

My wife drops her phone between 1-2 times a week (after doing some sleuthing), so her case has taken quite a beating. If you look at the pics below, you will notice that every corner has cracked, but not to the point where it has chipped off. The cracks are also internal allowing the case to still keep its structure intact. Think of it like the front windshield glass of a car. It cracks, but doesn’t shatter. The rigidity of the case is still good since putting the phone in and out of the case takes some effort, but it is looser than a new case like my 16 Pro Max.

The discoloration kind of matches the gold tones of the iPhone, and it would be interesting to see what would have happened if the phone were silver or black. Would it still discolor the same way?

I got Apple's clear case for my 16 Pro Max, and although it does look pretty nice, we will see what happens over time.

The important thing is after nearly 4 years of abuse, my wife's phone hasn't cracked or dented in the front or back. She has plenty of scratches on the screen, but that’s not the case’s fault. I would say I’m impressed by the durability of the clear case, even though it looks like hell. It’s usually on sale as well (got it at Best Buy for $39 vs $49).