This is the Mist theme by theRealPadster (Padster).
Inspired by the look of the GDM3 login manager, the goal is to have a theme that is as fully transparent and out-of-the-way as possible. This means a panel that blends right into the desktop, simple flat, transparent buttons, and the bare minimum when it comes to menus and elements that overlap the workspace.
The theme works on GNOME-Shell 3.14, 3.16, 3.18, 3.20, and 3.22; use whichever version you need.
Wallpapers used in preview:
-S.2 - by bo0xvn (http://bo0xvn.deviantart.com/art/S-2-413930214)
-68.II by bo0xvn (http://bo0xvn.deviantart.com/art/68-II-341330938)
-Grad by asiaonly (http://asiaonly.deviantart.com/art/Grad-465586687)
-A few other wallpapers I found online with no names or authors
Music in preview:
Jonathan Coulton's Greatest Hit Plus 13 Other Songs (http://www.jonathancoulton.com/wiki/Jonathan_Coulton%27s_Greatest_Hit_%28Plus_13_Other_Songs%29)
Cash Cash - Take Me Home (feat. Bebe Rexha) - https://play.google.com/store/music/album/Cash_Cash_Take_Me_Home_feat_Bebe_Rexha?id=Beavzz7imldy2cocg4cbraoeuku&hl=en
There are a couple known minor bugs in the GNOME 3.14 version, which don't show up in the 3.16 version:
-Occasionally, a modal dialog will have a full black background instead of dimming
-The panel clock has no shadow until you first mouse over it
-The date label doesn't show up until the second time you open the calendar popup
If you have a fix for a bug, please share it with me so I can update it.
The theme is on GitHub here: http://www.deviantart.com/users/outgoing?https://github.com/theRealPadster/Mist-theme
Available for Arch Linux on the AUR - https://aur.archlinux.org/packages/gnome-shell-theme-mist-git/
Free download at deviantART, just click "download", not "purchase"
11 months ago
22 April 2016:
-Added GNOME 3.20 version
26 January 2016:
-Added GNOME 3.18 version
14 September 2015:
-Added version with GNOME 3.16 support
-New look/functionality for certain elements in 3.16 version because of GNOME changes