https://medium.com/@nathangitter/reverse-engineering-the-iphone-x-home-indicator-color-a4c112f84d34

I noticed an unusual behavior of the iPhone X home indicator while working on my most recent app. The app’s background near the home indicator is purple. When the app launches, the home indicator is very light gray.

But something odd happened when I pressed the app’s “share” button, which opened a default iOS activity view (aka “share sheet”). When I hit the “cancel” button to close the activity view, the home indicator animated to a dark gray color.