what the hell are you talking about

For just a fraction of a second I considered showing you, but taking a screen shot… 🤦 I’m my defence, I’m suppressed to be asleep now.

Many phones used to have - some still have - a separate LED facing you that could light up to notify you of, uh, notifications. The first generation android phones just had green LEDs, eventually they all supported colour as well. Some OS’es or apps enabled you to set up per-app colour, blink/fade, and pattern configurations. Super neat, I was a huge fan.

On most modern phones [such apps] (play.google.com/store/apps/details?id=com.ragecon…) rarely work anymore, but on my OnePlus 5 I still have different colours for different notifications.