No custom CSS and no snippets.
Solarized theme no longer installs using Settings > Appearance > Community Themes.
I did install this on 0.11.13 default Obsidian Help vault about a week ago. I recently created a new vault (my primary notes vault) and Solarized doesn’t install. I tried on multiple test vaults as well without success. Other themes do install using Settings.
A potential server issue as it doesn’t seem to fully fetch as with other themes?
I downloaded Solarized from GitHub using Obsidian’s Community Themes window, then installed it successfully and now can load Solarized using Settings > Appearance > Themes.
Also, general info: GitHub’s Solarized is 6 KB and version via app Settings is 3 KB.
Hope this helps.