For those who dislike the glossy square tile backgrounds in the Unity Launcher icons and Alt-Tab Switcher, Without changing GTK theme, there’s a simple script called unity-flatify-icons to “flatten Ubuntu Unity’s launcher icons”.
The script does not flatten the application icons, it accurately removes the tile backgrounds for un-opened application icons, and for opened applications uses new flat style boxes.
It also removes the background cube from the Alt-Tab Switcher:
To get started:
1. Download the script from github page:
After downloaded the archive, extract it and you’ll get the folder.
2. Open terminal (Ctrl+Alt+T), run commands to navigate to that folder, and run the script:
While the script is running, type your password when it prompts and hit Enter.
To apply changes, just log out and back in.
Restore the original Unity Launcher / Alt-Tab
Just re-install the libunity-core-6.0-9 package will replace all the icons file with original. Open terminal and run command:
sudo apt install --reinstall libunity-core-6.0-9
Also log out and back in to see effect.