Starting in macOS Sierra (10.12), Mac users have the option of using Night Shift to automatically adjust the colors on a screen to a warmer hue after dark. It's believed that adjusting the colors may improve sleep when using a Mac right before bed. Night Shift can be turned on or off through two different methods. First, open the System Preferences via the Apple icon at the top left of the screen.

Night Shift Macbook

Navigate to the Displays panel and then select the Night Shift tab. If it's disabled the 'Schedule' will show that Night Shift is 'Off'. Click on the 'Schedule' dropdown and select either a custom time frame or choose 'Sunset to Sunrise'. As an alternative, Night Shift can quickly be turned on and off through the Notification Center. To activate it, click on the Notification Center in the top right of the menu bar or swipe with two fingers right to left from just off the right edge of the trackpad. Scroll to the top of the Notification Center and toggle the Night Shift switch to enable or disable it.