Dark Mode in iOS 13 offers a beautiful dark theme across the whole operating system. In Dark Mode, the system uses a darker color palette for all screens, views, menus, and controls, and it uses more vibrancy to make foreground content stand out against the darker backgrounds. Dark Mode is perfect for low-light environments and lets your eyes rest easier at nighttime. You can turn on Dark Mode by going to Settings > Display & Brightness. Select Dark to turn on Dark Mode. You can also set it to turn on automatically at night (or on a custom schedule) in Settings.