Inspired by Devon's repo I've created my own style for Joplin. It's nothing fancy, but should work with all dark themes. In the future I might add specific styles for other themes.

I've also added a sample.md markdown file, which I used for testing the css.

There are different ways you can install and use the theme.

• Clone the repository
• Run ./tcu

See the section below for a more detailed description of the utility.

• Clone the repository into your Joplin profile directory. If you don't know where it is, go to Preferences and it will show you the location.
• Create symlinks to the .css files. (Remove or rename your current css files, if they already exist.)
• Create a new branch for your own changes. This will make it easier when new updates are available.

cd ~/.config/joplin-desktop
git clone https://github.com/tessus/joplin-custom-css.git
ln -s joplin-custom-css/Dark/userchrome.css
ln -s joplin-custom-css/Dark/userstyle.css
cd joplin-custom-css
git checkout -b my-css
# make changes to the css files and commit them
# when a new update is available, merge or rebase
git fetch origin master:master && git rebase master

Currently there's only one theme in the repository, so there's no need to specify it.

A backup of the css files will be created automatically in case data would be lost otherwise.

tcu - Theme Config Utility

usage: tcu [-t|--theme THEME] [-p|--profile PROFILE_DIR] [-x|--no-theme] [-c|--copy] [-d|--debug] [-V|--version] [-h] [--help]

       -t, --theme THEME
           activate THEME
           available themes:
              dark
              none (same as -x, --no-theme)

       -p, --profile PROFILE_DIR
           Joplin profile directory

       -x, --no-theme
           deactivate current theme

       -d, --debug
           print debug information

       -c, --copy
           copy files instead of creating symbolic links

       -V, --version
           version information

       -h
           usage information

       --help
           this help

Many of the CSS snippets were taken from different topics on the Joplin forum. A few of them I used ad verbatim, others I had to adjust to match my theme, and others served as an inspiration.