With the exception of old movies, most of us are used to seeing our screens in full color. However, grayscale — in which you see nothing but black, white, or shades of gray — can be useful, even when it comes to your smartphone.
To begin with, people who are intensely colorblind will find a screen that has been switched to grayscale much easier to work with (since otherwise, certain colors can be difficult to distinguish). It may be good for the rest of us as well because grayscale is…