My (bold) assumption is that all devices have it. Simply speaking if you don't use dark mode or use the phone on medium high brightness level you will simply not see the flaw.
This is a known issue that Samsung needs to fix. It seems to me that it affects the entire Samsung S line. I have an S10 Lite and I also have this problem. Where it's gray, it's green. Black remains black because the screen is blanked out so black does not. This problem occurs when the brightness is automatic and very low.
An irritating problem. But that can be fixed with a simple update. Let's wait for Samsung's position as the problem is widespread. Here in Brazil they indicate technical assistance...but we know that updating is enough.
Android Security Patch Level: August 1st
I have a Galaxy S10+ and it's been perfect for a whole year. Just this afternoon, when I turned it on after using it all morning with no issue, I saw the green tint. It shows up as soon as it reaches the lock screen and is persistent everywhere, except for true black when the AMOLED is turned off. It started all of sudden and I have no clue why it started. I wiped the cache partition, booted into safe mode, did everything except factory reset. From other posts I've seen, people have said factory reset doesn't help either. Samsung support person said to take it into a repair center or a Ubreakifix center. Doubt that will do any good.
Other manufacturers claim that it might be a thermal issue.
Samsung will not fix this issue. It's apparently too much work and they want you to send in you device for repair (which btw. doesn't fix it at all). For that you can see the following: https://forum.xda-developers.com/showpost.php?p=82547643&postcount=23
He got his screen replaced at it was good for about a day but after that he saw the same issue again.
Well i did a research
Appears to be a problem with the Super Amoled Plus screens. All smartphones with this screen model are susceptible to this problem.
It looks chronic, especially when viewing a dark gray image with the screen brightness at low levels. We don't know if it is a specific lot or if it affects all devices, but the problem is global and Samsung still doesn't make a statement pretending that nothing is happening. Samsung only authorizes the exchange of the screens of users who report having the problem, but it does not help because it does not solve the problem. Im here with a S10 Lite with same problem. I called the warranty and i had two screen changes, but nothing.