[UbuntuGnome] Make Gnome Shell use theme icons instead of symbolic

I want to get rid of the ugly symbolic icons used in Gnome Shell and GTK3 themes and have them replaced with the icons from my actual selected theme.

I managed to do this for normal themes by adding "-gtk-icon-style: regular;" in the "gtk.css" of the theme. Save dialogs, Nautilus and other places now have the colorful icons I want.

Gnome Shell, however, seems harder. Any idea how I can make Gnome Shell use my icon theme instead of the built-in symbolic icons?