The Xbox Series X and Xbox Series S versions of Fallout 4 did not come with any high dynamic range at launch. This Seeking Tech guide will explain how you can enable the support for HDR.
1. If you haven’t done so already, download the latest patch for Fallout 4.
2. With the patch downloaded, make sure you have HDR10 enabled on your Xbox settings. To do so, open up the Settings App and then go to General > TV and Display Options > Video Modes.
3. Auto HDR should now be automatically applied to the game.