iOS 13 dark mode: New iPhone software update's biggest feature revealed in leaked screenshots

Black background looks set to improve battery life as well as stop

This Sept. 12, 2018, file photo shows an Apple iPhone XR on display at the Steve Jobs Theater after an event to announce new products, in Cupertino, California (AP Photo/Marcio Jose Sanchez, File)

The feature that is expected to be the most significant change in Apple's new software update for iPhones and iPads may have been revealed in new screenshots.

Apple is expected to introduce a system-wide dark mode when it reveals iOS 13 as part of its Worldwide Developers' Conference presentation, on 3 June. The feature will allow users to switch into a white-on-black option, rather than the usual black-on-white.

It is perhaps the most anticipated feature of those that have leaked about the new update. And it is an option that users have been asking for in recent years, for a variety of reasons.

As well as changing the aesthetics of the phone's software, a dark mode allows it to have less glare if it is used at night and can make it easier to look at details when using the screen. It also has the side effect of potentially saving battery – since the screens in the iPhone X and XS are OLED, they don't have to light up the parts of the display that are black.

In keeping with that option, the dark mode appears to be truly black, rather than the greyer colour sometimes used in dark modes in some apps. That should allow it to look better on OLED displays.

(9to5mac (9to5mac)

The leaked screenshots came from 9to5mac, which did not state where they had come from.

As well as showing the dark mode, they also illustrated the relatively unchanged look for the rest of the system. One feature that has changed and was shown in the images is the screenshot tool, which appears to have been redesigned and given some new features.

iOS 13 is set to bring a whole host of minor updates: changes to the Health app, updates to the way the iPad works, and a new app for finding your Apple devices and friends. But dark mode is expected to be the most obvious alteration, unless there are any major and unannounced features.