The first @pinafore dark theme (Ozark) was made by me?
It’s named after the Ozark Mountains region of the United States where I was born. It’s blue-based because I’m red-green colorblind and I’ve always loved the color of water reflecting the color of the sky just after sundown.
@ja2ke They're set on an instance-basis, so you go to Instances > (Your Instance) > and then there will be a list of themes. Currently I believe the dark themes are Ozark, Sorcery, and Cobalt (though there may be more now, I haven't looked!)