To get started, you’ll need an iPhone with Face ID running iOS 14.5 or later and an Apple TV or Apple TV 4K with tvOS 14.5 or later.
Turn on your Apple TV and open the Settings app.
Scroll down and open the Video and Audio tab.
Select Calibration.
Choose Color Balance.
Link:
https://www.macworld.com/article/344476/iphone-apple-tv-color-balance-calibration-how-to.html
