At WWDC 2016, we got a preview of iOS 10's bigger, bolder new design language, but unlike the new version of tvOS, dark theming was conspicuously absent from the forthcoming iPhone and iPad operating system. I understand why the company chose to exclude it, but quite frankly: This is a mistake.
The reasons for (and against) a dark mode
Partial interfaces with dark dressing have been found in the iOS 10 code base, which might indicate Apple is still exploring the possibility. Since it's only a few screens for a few apps, though, it also might indicate Apple hasn't really made up its mind.
Many assume a future iPhone or iPad will use AMOLED display technology, like Apple Watch, and will need a power-saving dark mode to make the most of it, also like Apple Watch. Since 3D Touch is currently dependent on LED, though, and a future iPhone or iPad is, well, still in the future, I'm going to address why it matters even in the here and now.
As Rene has written about time and time again, there are many good reasons to institute a Dark mode or system-wide Night theme. White screens are hard on the eyes, even with Night Shift enabled, and a Dark mode may also help users with accessibility issues more than the standard Invert Colors option (which helps, but not much). Several default apps in iOS already support a Night mode, including iBooks and Maps; many third-party programs offer the option, too. And iOS 10's custom Color Filters accessibility option already allows users to tweak colors across the spectrum for various vision ailments — why not create a version of that picker that only affects toolbars and widgets?
Additionally, the iPhone and iPad are the odd devices out at this point: The Mac has a Dark mode. Apple TV is getting a Dark mode in the fall. Apple Watch has a de facto Dark mode thanks to its OLED screen.
But despite all the potential good will toward a dark theme, there are still arguments against it. For one, it takes engineering hours to reengineer graphics, and there are quite a few apps that would need to be reworked. Think about iOS 10's new notification and widget bubbles: Third-party designers and developers specifically would have to make sure that any content they include looks great on both the light-grey theming and a darker option.
There's also the question of just how many users would turn the thing on in the first place: With so many exciting ongoing projects at Apple these days, it's hard to dedicate weeks and months to an ultimately-niche feature.
Choice is wonderful
Here's the thing: With over one billion iOS devices, "niche" no longer means what it once did. Even if only 1 percent enable a Dark theme on iOS 10, we're still talking about ten million devices. Even assuming only a fraction of those billion devices are actively used, we're still talking about hundreds of thousands of users. On iMore alone, an informal poll resulted in over 2600 people claiming they'd upgrade or switch to iOS from Android to have a Dark theme, with 829 "possibly interested" and only 292 "Not interested."
There's precedent for multiple themes to fit user choice, too: The iPhone and iPad have had them externally for years now. If you want an iPhone with a white faceplate or a dark one, you can buy one directly from Apple — no external mods required.
Multiple iPhone colors may have been discussed as a "niche" market at one time, but that time is long gone: iPhones, iPads, Watch models, and even Macs have adopted multiple case colors.
If the supply chain can manufacture hundreds of hardware options to help users find the best fit for their style and computing habits, I bet Apple can spare the engineering hours to finish up Dark mode and launch it alongside iOS 10. What say you?
We've filed this feature request with Apple. It can be found at rdar://19760524 (closed as a dupe of rdar://11786790). Do you want a system-wide dark or night theme? Let us know below!