Editor's take: Microsoft is currently testing a night mode option with select Xbox Insider members. Some could argue that these quality of life improvements are long overdue, but at least Microsoft is finally addressing them.
The new feature can be found in the settings menu for Xbox Insiders participating in the Alpha Skip-Ahead ring, an "invite only" program that allows members to test future Xbox OS builds. As highlighted in a quick demo from The Verge's Tom Warren, users with access to night mode can adjust the brightness of their display as well as how much blue light to filter out.
Additional options include the ability to disable HDR and modify your overall theme. These options can be toggled manually or set to activate on a schedule.
Brightness options even carry over to the controller and the console so you can dim the associated LEDs accordingly.
The idea here is to help make it easier to fall asleep after gaming, but such features could also be handy if you're sharing a space with someone else who is trying to get some shut-eye (think dorm or other roommate situation).
Barring any unforeseen circumstances, we can probably expect to see this feature trickle down through the various preview channels over the coming weeks or months before debuting as an official feature on all Xbox consoles in a future update.