While the iOS dark mode applies a dark-gray theme on most visual elements by default, it leaves certain visual elements light. If you're not okay with that, iOS 18 has two hidden appearance settings ...

1. On the iPhone's lock screen, touch and hold anywhere on the display until you see the Customize button. You'll need to ...

If you have an iPhone or iPad, you can turn on system-wide dark mode rather than activating it app by app. Your iPhone must be running iOS 13 or higher, and your iPad must have iPadOS.

Also, Dark mode finally applies to all of the iPhone's home screen, with options for coloring icons and affecting the brightness of the wallpaper image. Here's how to customize the looks.