Which macOS version introduced Night Shift for reducing blue light?

The macOS version that introduced Night Shift was macOS Sierra 10.12.4.

Apple released macOS Sierra 10.12 in September 2016, but Night Shift arrived later as part of the 10.12.4 update on March 27, 2017. The feature changes the display’s color temperature toward warmer tones during evening hours, reducing the amount of blue light emitted by the screen.

Night Shift was adapted from the feature Apple had introduced in iOS 9.3 in 2016. On a Mac, users could schedule it around sunset and sunrise, set a custom timetable, or adjust it manually through System Preferences, Notification Center, or Siri.

The feature is often confused with True Tone, which adjusts display color based on ambient lighting, or with f.lux, a third-party application that inspired similar blue-light reduction tools. Night Shift’s availability was also limited to supported Macs, generally models from 2012 onward, because it depended on graphics capabilities.