Transparency

If you want to adjust, add, or remove the transparency of an application, you'll need to edit the picom configuration file located at the following path:

$HOME/.config/picom/picom.conf

You'll then select an application using the xprop cursor:

xprop WM_CLASS

The cursor spawned by the command above will return the WM_CLASS of the application when you left-click over the application using the cursor and then the WM_CLASS string will be printed in the terminal in which the command was executed:

WM_CLASS(STRING) = "wireshark", "Wireshark"

[!NOTE] The application name is in the second field ("Wireshark").

The WM_CLASS contains the application name that you'll add to the following list that's in the picom configuration file:

opacity-rule = [
  "80:class_g = 'alacritty'",
  "80:class_g = 'qterminal'",
  "95:class_g = 'Polybar'",
  "95:class_g = 'Rofi'",
  "100:class_g = 'Thunar'",
  "100:class_g = 'Google-chrome'",
  "100:class_g = 'Firefox-esr'",
  "100:class_g = 'Firefox'",
  "100:class_g = 'Wireshark'"
];

[!NOTE] The variable class_g is used to define the transparency level.

Finally, you'll need to restart picom to apply the changes:

killall picom && picom --config ~/.config/picom/picom.conf -b