Dark Mode - Visual Design - iOS - Human Interface Guidelines - Apple Developer
In iOS 13.0 and later, people can choose to adopt a dark system-wide appearance called Dark Mode. 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.
https://developer.apple.com/design/human-interface-guidelines/ios/visual-design/dark-mode/
Alan Jo
