GnomishGray is a silver gray theme for GTK3. It also contains a matching GTK2 theme, that depends on the latest Murrine and Pixmap engines.
*** Current Dependencies ***
GTK3 = 3.12.X (works with 3.10 too)
gtk2-engines-murrine >= 0.98.1.1 (for GTK2)
Metacity >= 2.34 (for GTK2)
*** Important Notes ***
(1) Ubuntu users should disable "overlay-scrollbar" before using this theme, otherwise they might see blackened widget areas (a bug in overlay-scrollbar with a won't-fix tag). See help.ubuntu.com/12.10/ubuntu-h…
(2) Debian users may have to patch Cairo with 'server_side_gradients.patch' (bug #616308), which is included in other distros by default.
Feb 27 2014
Updated for GTK+-3.10 (should work with 3.8 too).
Dropped the Shell theme (its maintenance wasn't possible due to so many breakages).
Mar 4 2014
Added a matching Unity theme for Ubuntu Trusty.
Apr 18 2014
Removed the Adwaita dependency.
Updated for GTK+-3.12 (still works with 3.10).