HN top bar colours by popularity: https://news.ycombinator.com/topcolors

Wait, you can change the top bar color? That's news to me.

At certain karma thresholds, different things unlock. There's a list somewhere but I'm not sure if it's up-to-date.[0] It looks like top bar color can be changed once you hit 250 karma.

[0] https://news.ycombinator.com/item?id=853964

https://github.com/minimaxir/hacker-news-undocumented