An update to the official Wikipedia app for iOS is currently rolling out with an all-new "Black" reading theme for iPhone X. The new display feature, which accompanies the existing dark mode, has been developed specifically with OLED devices in mind, according to the developers.
Not only does the true black theme look good on the new iPhone's 5.8-inch display, it also potentially offers energy-saving benefits, since black pixels in an OLED panel basically switch off and consume far less power, giving avid Wikipedia readers another reason to use the official app over the website.
In addition to the new theme, the Wikipedia app update promises faster article loading and less data use. The speed improvements are mostly down to the fact that images are no longer pre-loaded and now only download when they're about to be displayed or saved.
Wikipedia is just the latest app to add a true black theme to its display options, with other popular apps like Twitterrific and Bear Notes also having included similar features in the last few weeks.
A native Dark or "Night" mode for iOS is one of the most popular long-running user requests, but Apple has yet to officially add support for such a feature, despite the added technological rationale for one on iPhone X.
The closest option for iOS 11 users is the "Smart Invert" accessibility feature, which is basically a tweaked version of the classic "Invert Colors" that aims to avoid inverting colors in images, although it's pretty inconsistent in this regard. The option can be found in the Settings app in General -> Accessibility -> Display Accommodations -> Invert Colors.