Theme Not Applying Everywhere

There are two steps involved, you likely did only the first step.

  • Select the theme on the Appearance settings.
  • Select the theme on the Window Manager settings.

TIP: Do not forget to set the icons too from the Apperance settings.

Theme Not Applying on Login Screen

See this answer on Stack Exchange.

Resolving Issues with File Permissions

You are likely to have issues with file permissions somewhere in the process. I resolve them by manually copying the relevant files to these locations:

  • /usr/share/themes
  • /usr/share/icons
  • /usr/share/wallpapers
  • /usr/share/lightdm/avatars

NOTE: The last directory does not exist by default so you will have to manually make it.

EXAMPLE: sudo cp ~/.themes/gruvbox-theme/ /usr/share/themes/gruvbox-theme/ -r

Sticky Keys

You might get nagging notifications about Stick Keys getting enabled. This is how I resolve them:

  • Open Accessibility settings then turn on Stick Keys manually, then turn it off.
  • Uncheck xfce4-settings-helper from Notifications settings' Applications section.

Using GTK Theme for Qt Apps

SELF NOTE: Don't. Not worth it since there are quirks here and there.

  • Install the dependencies: bash sudo apt install qt5ct qt5ct-style-plugins
  • Setup your .profile (.zprofile if using Zsh): bash export QT_QPA_PLATFORMTHEME=qt5ct
  • Log out and log back.
  • Open qt5ct then select gtk2 theme with default colorscheme.
  • Apply.

Log out Menu Not Following GTK Theme Under i3 WM

I don't know what exactly the cause is but the fix is tweaking your session startup apps.

Configure your startup session as shown and then login. It should work.

NOTE: You might also need to switch to "Xfce" from "Xubuntu" in the login manager before doing this.

Exit TTY

Press CTRL + ALT + F7.

Flameshot Not Copying to Clipboard

See this issue for more information.

The fix is to make sure a flameshot daemon is running whenever you take a screenshot. To run a daemon you can simply execute flameshot. You can, for example, put it in the startup list in the Session and Startup settings.

Bluetooth Icon Missing

sudo apt install bluetooth blueman

Set blueman-applet in the startup list.

Some Menus Have Black Borders on i3

Append ~/.config/gtk-3.0/gtk.css with:

menu,
.csd .menu,
.csd .dropdown,
.csd .context-menu {
    border-radius: 1px;
}

This will remove round edges from those menus to resolve the issue. This is more of a workaround from that view.