You might already be aware that Linux system vendor System76 has announced its own Linux distribution Pop!_OS. It is based on Ubuntu and boasts of an aestheticĀ icon and theme pack among other features.
While you’ll have to wait for the release of Pop!_OS stable version, you can surely use the Pop icon and Pop GTK theme as both of them are quite stable. And if you are thinking why should you do that, let me share the screenshot of my desktop using this theme and icon set.

It looks stunning, isn’t it? So if you have decided to give it a try, let’s see how to install Pop icon and GTK theme on Ubuntu.
Install Pop icon and GTK theme on Ubuntu
You can watch this video to see how to install and use Pop icon and GTK theme.
I am using Ubuntu 16.04 Unity in this tutorial but you should be able to use this icon and GTK theme on other Linux distribution especially if you are using GNOME desktop environment.
Option 1: Installing Pop Icon and GTK theme using official PPA
System76 provides its official PPA for Pop icon and theme:
sudo add-apt-repository ppa:system76/pop
sudo apt update
To install both icon and GTK theme together, use the command below:
sudo apt install pop-theme
To install only icon theme, use this command:
sudo apt install pop-icon-theme
To install only GTK theme, use the command below:
sudo apt install pop-gtk-theme
Option 2: Installing Pop Icon and GTK theme using unofficial PPA
However, I found the official PPA broken. And for this reason, I used PPAs from Noobslab.
To install the Pop icon theme, use the commands below:
sudo add-apt-repository ppa:noobslab/themes
sudo apt update
sudo apt install system76-pop-gtk-theme
To install the Pop GTK theme, use the following commands:
sudo add-apt-repository ppa:noobslab/icons
sudo apt update
sudo apt install system76-pop-icon-theme
Using Pop icon and GTK theme in Ubuntu
Once you have installed the icon and themes, you can easily change the current icon and GTK theme. In Unity, you can use Unity Tweak Tool.
If not already installed, use the command below to install Unity Tweak Tool:
sudo apt install unity-tweak-tool
Once installed, just open Unity Tweak Tool and go to Theme and Icon to use the newly installed theme and icon respectively:

Just select the desired icon or theme to use it. This gif should help you with that:

You can also read this article to find how to install themes in Ubuntu Unity.
For GNOME users, the process is similar. You will be using GNOME Tweak Tool instead of Unity Tweak Tool. Read this article to see how to change themes in GNOME.
Add System76 wallpaper
Your system might already be looking good. What we need to do now is to change the wallpaper. A wallpaper plays an important role in the overall appearance of the system and since the Pop theme has an azure shade, azure shaded System76 wallpaper just blends perfectly with the Pop theme.
You can download this wallpaper from the link below:
You can find more System76 wallpapers here.
Once you have downloaded the wallpaper, just right-click on it and select “Set as Wallpaper” option. Et, voila! Your system will have a perfect look :)
Did you try Pop Icon and GTK Theme?
Honestly, I really liked Pop theme suite. To me, it deserves to be on the top of the list of the best icon themes for Ubuntu. What do you think? Did you like it? If yes, then why not share a screenshot of your desktop?
I have some issues in ubuntu 20.04.
The ppa from system76 installs many other packages. It actually gives you parts of the pop os, not only the theme for gnome.
The noobslab ppa is not working with 20.04. I get an error stating that the repository has no Release file.
How to safely get the pop theme on Ubuntu and 20.04 then?
The official repo caused me issues where it was replacing my kernel with the Pop_OS! kernel and messing with secure boot. Unofficial PPA much better…
How do add the repo to ubuntu 18
The command should work for Ubuntu 18.04 as well.