The latest releases from the smartphone OEM OnePlus, the 8 and 8 Pro, have been issued new versions of their Android skin, OxygenOS. These updates are intended to fix the "green tint" defect reported by some users. They have also been released to enhance some aspects of the phones' cameras.
https://www.notebookcheck.net/OnePlus-new-software-update-for-the-8-and-8-Pro-may-fix-the-green-tint-issue.463700.0.html