The display uses white OLEDs and color filters, so that each pixel is composed of four sub-pixels color (RGBW), as shown in the second illustration.
In September last year, Japan Display company introduced another display type OLED, which uses the same technology. Its size is equal to 4.5 inches, and resolution - 1280 x 720 pixels, which corresponds to the density of 326 pixels per inch. For comparison, the exact same density has the screen of Apple iPhone 5, but the screen smartphone Samsung Galaxy S 4 has a density of 441 pixels per inch, because the resolution of 1920 x 1080 pixels of its size is 4.99 inches. Note that Apple iPhone 5 screen - LCD, and Samsung Galaxy S 4 a Super AMOLED display OLED.
The new display is designed for high end smartphones.