I've lurked here and on other discussion/aggregation sites for years (I've apparently been here 10--oof) and only recent started commenting a little more. This whole time I didn't realize the top color could be set. I noticed it in my profile a couple days ago and thought it was an entirely new site feature.

Seeing all this info I was unaware of laid out in front of me makes me wish there was a docs page linked in the footer, like Tildes has.