Flatpak is a bit limited in what it can access, but you can use your preferred custom GTK theme on Zorin OS 15 or Zorin OS 16 flatpaks.
There are a couple of caveats.
- The theme in question must be located in your Home .themes directory. Flatpak is utterly blocked, by design, from accessing /usr/share/themes
- The theme will not change when you use your Themes or Settings manager to switch themes. You must manually use CLI to go in... and change it, too.
- Since Flatpak mostly is on GTK4, many GTK3 themes may no longer work on Flatpak apps.
First, create (if it does not exist already) a home themes directory by right clicking an open area within your File Manager in Home
and creating a new folder. Name it .themes
Now, move or extract your custom gtk themes into that directory.
Give flatpak access:
sudo flatpak override --filesystem=$HOME/.themes
Now that it has been given permission to view a directory on your system that you use...
You can instruct it which theme to use. Remember, this is the only way, currently, to tell flatpak to use a theme other than the one it wants to use. So if you switch themes later, you must repeat this. Replace THEME-NAME
with the exact theme name as it appears in your .themes
directory.
sudo flatpak override --env=GTK_THEME=
THEME-NAME
Kill any flatpak applications running and relaunch and they should now be sporting a new look.
Revert all changes with:
sudo flatpak override --reset
Using Flatseal
Install Flatseal:
flatpak install flathub com.github.tchx84.Flatseal
Under All Applications tab
, scroll down to Filesystem
You can set All system files
or you can specify the individual theme files. Click on Other files
and add the directories:
- ~/.themes
- ~/.icons
Add them one at a time. Once you enter one in a field, just click the (+) button again to add the next.
Restarting the app should show your system theme and icons.