I have LG Aristo that suddenly turned black/white
I tried everything, turning it off and back on, adjust settings, searched internet for help, etc...
Nothing seemed to work
I pulled down the screen at the top which give notifications and at the very top has signs of features that can be turned on and off by touch.
ie: WiFi strength, Sound, Bluetooth, Location, Rotation, Sync, Flashlight, Airplane Mode, Data, Battery Saver, Color Inversion and "COMFORT VIEW".
Clicked on 'COMFORT VIEW' and (((POOF))) everything went back to color.
Felt like I was in Wizard of OZ. LOL
Hope it helps fix your issue.
Have a GREAT Day!!!