HDR plus
How do I pick hdr plus in new Apple TV
Apple TV 4K, tvOS 15
Question marked as
What is your model Apple TV? Identify your Apple TV model - Apple Support
A1842 and A2169 can be set to SDR, HDR (=HDR10) or Dolby Vision, if such a screen is attached. Only valid choices are offered.
A2737 and A2843 can probably be set to SDR, HDR10, HDR10+, or Dolby Vision, if such a screen is attached. I think; I haven’t seen the screen shots yet.
Settings﹥Video and Audio﹥Format﹥…
and/or
Settings﹥Video and Audio﹥Match content﹥Match Dynamic Range﹥On
Adjust video settings on Apple TV - Apple TV user guide - Apple Support
About 4K, HDR, HDR10+, and Dolby Vision on your Apple TV 4K - Apple Support