>>268536168
>RGB OLED is possible, but no-one makes them

The reason for this, and the reason pentile exists is because with current OLED tech, the green sub-pixels die out about twice as fast as the red and blue ones do. To alleviate this, they use a pentile layout which allows for two green sub-pixels per pixel, each at half illumination. The theory being that 2 at 50% will last as long as the red and blue subpixels at 100%. You won't see too many RGB striple layouts for OLED until the green pixel problem is solved.