By default, the background on the phone is black which comes out completely dark on an AMOLED screen, because the screen technology can
illuminate individual pixels for precision blacks sat next to bright whites.
Not exact matches
It's worth pointing out, however, that the S7's AMOLED 1440 x 2560
pixel display, allows the phone to light up
individual pixels as needed, which means it doesn't use as much battery power as it would if the screen was always completely
illuminated.
IPS LED - backlit LCD screens used in the iPhone 8 and iPhone 8 Plus are constantly
illuminated by blue LED lights, whereas OLED and AMOLED on the iPhone X and Samsung phones are
illuminated by
individual pixels.