Dark vs. Light Theme Battery Stats on SAMOLED

Minor tangent: I'm not sure how he defends his contention that SAMOLED > LCD by noting that he didn't test anything but SAMOLED in the comments. I realize he wasn't testing anything else and I'm perfectly willing to believe that SAMOLED is more efficient but he still claimed X and when asked for evidence punted.

http://blackle.com/

http://en.wikipedia.org/wiki/Blackle

If you are using a LCD the color of your pixels doesn't matter. Ok, it might matter a little bit but not much and it's not as easy as saying that white uses more power than black. It might even be the other way around.

In an LCD the color is determined by a liquid cristal filter that can be turned on or off and dimmed. The filter itself needs hardly any power, however. Not compared to the actual light that shines through that filter.

The light comes from LEDs or CFLs (I guess in principle you can use any light source but those two have useful form factors and need less power than, say, incandescent lightbulbs) behind that filter. And that light is always on. Some TVs have local dimming to make the blacks blacker in certain regions of the image, but computer monitors don't.

So by using a dark theme, all you influence is the filter, not the actual lights. As you might know, covering up a lightbulb so you don't see it's light anymore doesn't magically make the lightbulb consume no more power.

AMOLED displays work differently. There the pixels themselves light up or don't. They are like a matrix of thousands of minuscule lightbulbs you can individually turn on or off.