This new OnePlus 8 Pro update might fix that green tint issue
From Androidauthority.com

The OnePlus 8 Pro is now getting the Oxygen OS 10.5.5 update.
By Adamya Sharma
Published on April 27th, 2020
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Tint News

The OnePlus 8 Pro is now getting the Oxygen OS 10.5.5 update.
By Adamya Sharma
Published on April 27th, 2020