In past, you may have used Faenza icon theme or you still have it set on your desktop. Delft icons are revived version of Faenza and forked from Faenza icon theme, maybe it is not right to say 'revived' because it looks little different from Faenza theme and at the same time it stays close to the original Faenza icons, it is released under license GNU General Public License V3. The theme was named after a dutch city, which is known for its history, its beauty, and Faenza in Italy. The author who is maintaining Delft icons saw that Faenza icons haven't been updated from some years and thought to carry this project. There are some icons adopted from the Obsidian icon theme.
Delft icon pack offer many variants (Delft, Delft-Amber, Delft-Aqua, Delft-Blue, Delft-Dark, Delft-Gray, Delft-Green, Delft-Mint, Delft-Purple, Delft-Red, Delft-Teal) including light and dark versions for light/dark themes, you can choose appropriate one according to your desktop theme. These icons are compatible with most of the Linux desktop environments such as Gnome, Unity, Cinnamon, Mate, Lxde, Xfce and others. Many application icons available in this icons pack and if you find any missing icon or want to include something in this icon pack or face any kind of bug then report it to creator.

Delft Delft icons
Delft Delft icons
Delft Delft icons
Delft Delft icons

Available for Ubuntu 18.10 Cosmic/18.04 Bionic/16.04 Xenial/14.04 Trusty/Linux Mint 19/18/17/and other related Ubuntu derivatives
To install Delft icons in Ubuntu/Linux Mint open Terminal (Press Ctrl+Alt+T) and copy the following commands in the Terminal:

That's it
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