Digital Versus managed to get a macro photo showing LG's WRGB OLED TV sub pixels. LG's structure uses four white sub pixels (made from yellow and blue emitters) with color filters on top: white (unfiltered), red, green and blue. As you can see from the photo, the white sub pixel is actually larger than the colored ones. The white sub pixel is added to increase brightness and efficiency.
LG's 55EM9700 is a 55" Full-HD Oxide-TFT panel that features 100,000,000:1 contrast ratio and fast response time (1,000 times faster than LCD according to LG). The panel is only 4mm thick and weighs only 3.5Kg.