When exiting the game, or alt+tab out of game, all my screen colours are inverted.
On exit: ctrl+alt+del, open task manager, colours return to normal, close task manager with no changes.
On alt+tab: colours inverted, return to game, colours return to normal. Haven't tried ctrl+alt+del after alt+tab, I assume it would fix it like when I exit.
Whenever I pasted screenshots into msPaint the pasted pic had normal colours, so included pic is photo of screen taken from phone (apologies for flash flare in middle of pic)