Always liked Nord.
Everforest is my current favorite.
Solarized has been around for eons. As well as Gruvbox, but you may need to do more legwork for that one.
Catppuccin and Tokyo Night have some nice palettes, too.
And no - I'm not aware of a solid centralized place to find high quality, multi-app color schemes like these.
This tells me LibreOffice has become a threat to Microsoft, and I'm here for it.
If anyone else is curious what it's like, LibreOffice's site is here. Highly recommend.