Greybird is the default theme of Xubuntu. The new version of the theme (3.20.0) now supports GTK 3.20 as well and it has been ported to SASS.
The creator of the popular Arc GTK theme released a new official Arc icon theme.
Unity doesn’t have an option to apply global dark theme but it’s easy to resolve. Here’s how to apply Adapta dark on Ubuntu.
Linux Mint 18 is going to introduce a new GTK and icon theme called Mint-y. The GTK theme is based on Arc and the icon theme is based on Moka.
Adapta is a shiny new material design like GTK theme. It supports numerous desktop environments including Gnome, Budgie, Unity and Cinnamon.
A slightly modified version of the beautiful Arc GTK theme has been released with OS X styled window buttons.
The new version of Edge GTK theme give Nautilus a new look. GTK 3.20 support is coming soon.
Horst3180, the author of Arc GTK theme is now working on an amazing new icon theme. See a screenshot of the icons.
elementaryPlus is an amazing addition to the default elementary OS icon theme. It adds office suite icons, third party app icons and indicator icons as well.