When we first broke the news on the BlackBerry 10 L-series and N-series, it was shown that RIM would be using OLED technology for the touchscreens. In these slides, RIM describes why they’ve chosen OLED for BlackBerry 10 devices. We have copied the information verbatim.

The absolute blackness of the OLED display can create a powerful illusion of screen and hardware blending. Use pure black wherever possible to optimize power consumption, prevent Burn-in, and as an aesthetic effect of actual black (i.e. no backlight).

When there is no visual distinction between the bezel and the screen, a screen can use smaller margins. Selected core components, such as the Action Bar, will also be adapted to impression of a unified surface through a full black background.

Instead of thinking of each OLED pixel as a flashlight, in this case think of each one as a candle. When you burn a candle it will slowly burn down and never recover. The higher the flame on the candle, the faster it will burn down. The same is true for OLED. Brighter pixels will burn faster with the additional complication that each sub pixel burns in at a different rate.

Certain core components has elements that are consistent across most screens of the whole device. To prevent burn-in, we need to programmatically make slight adjustments of their contrast strength and potentially position over time. This applies to for example the Status Bar icons and back button in the Action Bar.

In general, the dark an image is, the less power it will use. If you think of each OLED pixel as a mini-flashlight, the more flashlights you turn on or the brighter you shine them, the shorter the battery will last. Black themes and backgrounds are preferable for OLED-displays.

White theme may still be used to ensure readability when focus is on reading content for longer time (Email and Docs To Go). When using white theme, color values of white backgrounds will be programmatically adjusted towards gray, by the device itself. Single core components and smaller areas will not be possible to automatically adjust with good result, hence they need to be adjusted upfront. 

There you have it on how OLED will be very effective at saving battery life in BlackBerry 10 smartphones. Will you like the fact that you won’t necessarily be able to tell screen from device?