Sub-pixel Layout Test

In short Every pixel is made of separate red, green and blue sub-pixels, and their order across the screen is usually RGB but is BGR on some panels and an irregular pentile arrangement on many OLEDs. That order matters for one visible reason: sub-pixel anti-aliasing, which sharpens text by lighting individual sub-pixels, has to know the layout. If your text has orange and blue colour fringes, it is being rendered for RGB order on a BGR panel or the reverse. On Windows, running the ClearType Text Tuner usually fixes it; on a BGR panel, greyscale anti-aliasing is often cleaner than trying to correct it. To actually see the layout, photograph the white lines with a phone camera held very close, or use a magnifying glass — the order of the coloured stripes within each line is the answer. Pentile OLED panels are a separate case: they share sub-pixels between neighbouring pixels, which is why text on some phones looks slightly fringed no matter what setting you use.