Many moons ago in another life, the office word processor programs had a menu of settings - white letters on black background, black on white, white on blue, black on gray, etc. And most had a preference and just reset it while complaining that the last person had set it to something else … Lather, rinse, repeat. So I added a new setting in the middle: black on black. Then I watched while people would flip to the menu, say: “Oh, that’s new!”, select that setting, then sit there staring at a black screen, trying to figure out what to do next. The fun ones were the ones who would start typing, then wonder why nothing was showing up on the monitor. The really fun ones did it more than once.