Screens that use organic light-emitting diodes, better known as OLED and AMOLED, have a unique method of image production. When instructed to display a "black" color, the individual pixel cells are physically turned off, providing the stunning blacks seen on OLED-equipped devices like the Galaxy S II, DROID RAZR and the original Nexus One. Interestingly, this also means that displaying a mostly black image on an OLED screen also draws less power than a white or full-color image. To take advantage of this technological quirk, an intrepid modder on XDA
has set about modifying all of Google's core Android apps to save the maximum amount of battery on OLED phones, via the simple expediency of reversing the color scheme.