Source (link to git-repo or to original if based on someone elses unmodified work): https://github.com/lucifer-morningstar/openlotus-theming-project
A clean, simple icon set for Inkscape on dark themes.
The default Inkscape set uses color indiscriminately making it impossible to use it as a visual cue. The overall philosophy was to strip the set of unnecessary color and complexity freeing them up to communicate additional information to the user. The semi-translucency has a couple of beneficial effects for professional users. First it reduces distraction the way darkening a browser window around a video for the same reason. Professionals already know where their tools are, usually use keyboard shortcuts, and don't need extra hints. The side-effect of the semi-transparency is that it will look nice with any colors in most dark themes.
It's base color is a slightly off-white grey at a standard 60% opacity. For this reason it's likely not suitable for light colored UI themes.
Installation on Linuxes (non-KDE): Simply copy the icons.svg file to $HOME/.config/inkscape/icons/
On Windows: A custom icons/icons.svg file can be loaded from the user Inkscape preferences directory (it will override existing icons from the shared icons file, and fall back to icons from the shared icons file if some are missing in the custom one).
On KDE's Plasma: use the first method or install the OpenLotus Theming Project's Linux iconset when it's finished. I'ts on github while in devel if you want to try it now. I'ts useable, basically.