Wavelog supports theming, and several themes are included in the release. To set a theme, you must edit your user account and set the theme there.

To set a public theme, you need to go to admin and global options. Set your wanted theme under appearance.

If you want to make your own theme, make a folder under assets/css, and place the edited files there (bootstrap.min.css and overrides.css). To add this as a selection in Wavelog, go to options and themes. Add the theme name and the folder name there. Your own theme should now be available to choose.