I see that when I'm reading text on white screen. I see it also on different colours when I'm scrolling web pages.That is probably normal. It's not normal to view an all white screen. When you put a normal display on it, you shouldn't notice anything unusual.
I'm aware but we checked newer model and it was better so I'm thinking is it production bug, or maybe some pressure fault due to cleaning or in transport. And below it is newer 14" so maybe it is only in 16"? hmIf it bothers you a lot, ask the seller if they'll refund your money. If they won't, you have few options, unfortunately, other than adjusting brightness and just learning to live with it. If you use the machine primarily at home, you can run the MacBook in clamshell mode using an external display. I still think it looks normal. You might be able to resell it for close to what you paid and find another one that suits you better.