Arranging app icons ... the color of icons on the home screen. This only works with app icons in dark mode, though. Press and hold the background to enter jiggle mode, tap the Edit button from ...

start with a long press on your home screen in an area where there is no app icon for a couple of seconds. Your apps will jiggle and show a (-) remove button in the upper left corner of each icon.

You’ll see an Edit button in the top-left corner; tap it, and then select Customize. You’ll now see two sliders: one that chooses a color for your icons and another that goes from light to dark.