Custom themes not in preferences

I feel like this is a stupid oversight on my part, but I cannot get a custom theme to show in the Preferences dropdown.

Theme files are present in root/themes.local. I even moved them to root/themes to see if they would load, but no luck.

TT-RSS 18.12.

Try this: https://tt-rss.org/oldforum/viewtopic.php?f=1&t=3653

this has been removed a while ago though

op you need to at least upgrade to latest version first, otherwise it’s unlikely that i’ll be able to help you

also theme files should be named like themes.local/mytheme.css, post ls themes.local etc

Whoops, I had no idea. Disregard it then.