apple tv unable to adjust color balance all i get is unsupported device ?

Color balance calibration on the Apple TV box with tvOS 14.5 or later, requires an iPhone with Face ID and iOS 14.5 or later, that uses the same Apple ID account.

Identify your iPhone model - Apple Support

Calibrate video or audio - Apple TV user guide - Apple Support

The iPhone 8 series does not have Face ID so it cannot be used to calibrate the Apple TV. That’s why you are getting the ‘unsupported device’ message.