Windows 10 shortcut to activate black & white (grayscale) mode
Especially if you are interested in photography and movies you may like to test grayscale view instantly to decide how your picture looks better.
For this or for any reason, if you like to change from color to black & white instantly, Windows provides natively a keyboard shortcut, Win+Ctrl+C. It’s a toggle shortcut; typing it changes from color to grayscale and the opposite.
Note that this keyboard shortcut needs to be explicitly activated, otherwise you are not able to use it. To activate it go to Windows Settings > Ease of Access > Color filters and check the box to “allow the shortcut key to toggle filter on or off”.
Note that instead of changing between color and grayscale you can use the same key to invert colors or invert grayscale, two modes that are used less often, however the system provides also this option.