Hi @FlightFreak,
Thanks for the inquiry, and welcome to the Roku Community!
Just a heads-up: Roku TV is designed to play content at the best quality possible, including HDR and Dolby Vision when available. You can't fully disable HDR, but you can customize how it looks. While playing something, press the * button on your remote, go to Picture Settings, and adjust the HDR mode (Dark, Bright, or Normal) to find your perfect setting.
If you have any more questions, feel free to contact us. We’ll continue to help you. I hope this helps!
Best,
The Roku Community Team
John
Roku Community Moderator
