Hi there! We have a Samsung UA55NU7100 which is two years old, and suddenly has a display issue. The TV's own menu is fine, going through Netflix, Amazon Prime etc menus all appear fine, but as soon as a TV show is playing it is extremely white/bright with high contrast and some colours look like they would in a negative photo of the screen.
A Playstation 4 and Switch connected via HDMI 1 and 2 also display completely in the same bright/white unwatchable fashion. We've tried different cables to connect them with no success. We've also tried changing the brightness/contrast/backlight etc settings and ran the self-diagnosis picture test, none of which helped (and the picture test, inherent to the TV, looked fine).