The top bar used to be transparent in Ubuntu when it was Gnome 3.32. Though it is now a solid color, you can easily make it transparent again.
Without installing any configuration tool, the left (or bottom) dock background transparency is easy to set via a single command in terminal (change 0.2 from 0 to 1):
gsettings set org.gnome.shell.extensions.dash-to-dock background-opacity 0.2
However, for the top bar transparency you need to install an extension or use another Gnome Shell theme.
Enable Top Bar Transparency via Gnome Extension:
1. First open
terminal by pressing Ctrl+Alt+T on keyboard. When it opens, run command to install the
chrome-gnome-shell package if you don’t have it.
sudo apt install chrome-gnome-shell
2. There are quite a few extensions that can do the job. While some are not updated for current Gnome version (though it may still work), here are 3 of them that supports Gnome 40 (ship in Ubuntu 21.10):
- Dynamic Panel Transparency: Transparent top bar when there’s no maximized app window and no window hitting the top.
- Transparent Top Bar: do same to Dynamic Panel Transparency extension, but no custom settings.
- Transparent Shell: transparent top bar, dash, workspace view.
Just choose one and click the link to go to the extension web page and turn on the toggle icon to install it.
Don’t see the toggle icon? Click the link “Click here to install browser extension” to install browser extension and refresh the web page.
The extension should change the panel transparency once you installed it. And you can configure extension settings using Gnome Tweaks tool.
Get transparent panel via Gnome Theme:
There are also a few Gnome Shell themes that change the feel and look of you desktop panel. And Transparent Shell Theme is one of the most popular.
With the theme, drop-down menus as well as dock icon context menus also become transparent.
1. To install the Gnome Theme, click the previous link and download the source tarball.
2. Extract and move (or copy) the source folder to .themes in your user Home folder.
Press Ctrl+H to show hidden folders, and create .themes folder if it does not exist.
3. Finally apply the theme in Gnome Tweaks -> Appearance. If the option is greyed out, install user themes extension.
That’s it. Enjoy!