NixNote Themes - robert7/nixnote2 GitHub Wiki
Theme-ing / dark setup
Rudimentary theme setup is possible (see menu Edit/Theme) - e.g. "dark mode".
Currently this only works with the native packages (for Ubuntu: install from PPA). At present it doesn't with the AppImage packaging - more info in this thread. Also "dark colors" work only if you install and activate dark system theme - e.g. "Arc-dark".
Note: for Ubuntu 18.04 you may need to configure Qt5 to use Gtk+ style - see Get Qt5 Apps To Use Native Gtk+ Style In Ubuntu 18.04.
See also: