How to check if iPhone 7 plus display is genuine?

I recently bought a used iPhone 7 plus. After receiving it, I realized something was off about the display. It had a weird bluish tint and turns out, getting a non-genuine display panel can do that. Is there any way to check if the display is non-genuine?

Also, the seller said they had the battery replaced with a genuine one but I’m starting doubt this as well.

Any suggestions would be extremely helpful, thanks!