userChrome.css file for a Zotero dark theme. Suggestions for improvements are welcome.

New version available for Zotero 6. Created for Zotero 5.0.92. Windows 10 compatible.

To use it follow the following steps:

1. Go to your user Profile folder
   • Windows users: C:\Users\User_name\AppData\Roaming\Zotero\Zotero\Profiles\user_profile.default\
   • Linux (Flatpak) users: ~/.zotero/zotero/XXXXXXXX.default/
2. Create a chrome folder
3. Place the userChrome.css file in there
4. Start Zotero and enjoy

I encourage everyone to play around with this and try to improve on it and theme things that I didn't manage to. These include the following elements:

• Scrollbars (that is usually done via userContent.css in Firefox but it doesn't work in Zotero)
• New PDF reader
• Note editor (in Zotero 6)
• Menu colors
• Sub-categories in the Preferences dialog. Not satisfied with the preferences dialog but it's the best I could make it

If you wish to explore for additional elements to alter:

1. Go to the folder of my Zotero install (C:\Programs(x86)\Zotero)
2. Copy the zotero.jar folder to another folder
3. Use 7zip to unzip zotero.jar to a zotero folder
4. Go to D:\X\zotero\chrome\skin\default\zotero
5. Look at ALL .css files in this folder
6. Start testing different pieces of code to change the defaults in the userchrome.css file.

To implement a dark theme in the Note Editor in Zotero 5 (credit to 10cks) follow the subsequent steps:

1. Start Zotero
2. Go to Preferences -> Advanced -> Config Editor
3. Select "I accept the risks!"
4. Search extensions.zotero.note.css and double-click it
5. Insert the string in the Note_editor_css.txt file
6. Click "OK" or close the dialog box
7. Restart Zotero.

Dark theme compatible with MacOS is available as a fork maintained by yiktungho: https://github.com/yiktungho/Zotero-Dark-Theme/tree/mac-patch