6 themes for Inkscape

Installing in new versions of Inkscape after v. 1.0

Place the Inkscape icon theme in usr/share/inkscape/icons
Edit - Preferences - User Interface - Theme, to change the icons

Or, select the option from the list - use system icons.

Installing in old versions of Inkscape v. 0.48

Place the Inkscape icon theme in usr/share/icons
Select by name in the system settings to change icon themes.

Full icon themes:

Acid https://www.opendesktop.org/p/1616609

Snowy https://www.opendesktop.org/p/1311570

Uniform+ https://www.opendesktop.org/p/1012468

Yellow square https://www.opendesktop.org/p/1150789

Smaragd https://www.opendesktop.org/p/1012162