According to Beaufort, “Chrome OS Night Light new feature aims to ensure reduced strain on the eyes and improved sleep by allowing you to limit the amount of blue light your display uses.” This is similar to what other companies have introduced to their operating systems in the past, such as Apple with the Night Shift mode that lets users reduce the amount of blue light emitted from their iOS device’s display.
From what we can tell, users will be able to turn the feature on and off and set a schedule so that it will automatically shift in and out of Night Light mode depending on the time. Users can also further adjust the color temperature that they prefer. However this feature is currently undergoing testing as part of the Canary build, which means that it won’t be available to users running the main release of Chrome OS.
That being said it is a useful feature and we expect that Google should eventually push it out to the main build of Chrome OS in a future update, so do keep an eye out for it if this sounds like a feature you might be interested in.