My wife's main screen

[SteveA]

My wife's main screen has gone Black and White what do I have to press to change it back to colour

[Neo001]

It could be that greyscale is turned on in Settings > Accessibility > Visibility enhancements > Colour adjustment, or bedtime mode is enabled which has one the actions to turn on greyscale during set times.

[Richmar83]

Try either of these:
1. Search 'grey scale' within settings and turn off the colour adjustment if it's enabled.
2. If above hasnt worked, have you got dark mode enabled? You can turn it off / on via quick panel at top

[pinkk]

Has she turned on "bed time mode" from the clock settings?

[Robot-]

Maybe power saving is on?