Why OLED Smartphones Backgrounds Are Black By Default

While reading an e-book about Windows Phone programming, I came across a paragraph that caught my attention. From Microsoft Press’ e-book titled Programming Windows Phone 7, it stated that:

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OLEDs are different from flat displays of the past in that power consumption is proportional to the light emitted from the display. For example, an OLED display consumes less than half the power of an LCD display of the same size, but only when the screen is mostly black. For an all-white screen, an OLED consumes more than three times the power of an LCD.

Because battery life is extremely important on mobile devices, this characteristic of OLED displays implies an aesthetic of mostly black backgrounds with sparse graphics and light-stroked fonts. Regardless, Windows Phone 7 users can choose between two major color themes: light text on a dark background, or dark text on a light background.

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This tidbit is very informative. This could be why the default background color of smart phones is black. What do you think?

(photo taken from the EPMM website).