/usr/share/avant-window-navigator/applets/volume-control/themes/Black/index.theme is in awn-applet-volume-control 0.4.1~bzr1507-0ubuntu7.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 | [Icon Theme]
Name=Black
Directories=scalable
[scalable]
Size=48
MaxSize=256
Context=Apps
Type=Scalable
|