Hi, @pollardt3
Thanks for inquiring, and welcome to the Roku Community.
The Roku Select Series TV's brightness is based on your environment and your viewing preferences. To explore more about the Roku TV 40" Select, you can visit this link at Roku Select HD TVs.
We hope you find this information useful and if there's anything we can do to assist you further, please let us know.
Best wishes,
Kash
Takashi O.
Roku Community Moderator