This New Icon Theme Offers Adwaita-Style Icons for 3rd Party Apps
The new ‘MoreWaita‘ icon set does just that.
This community-based icon pack seeks to faithfully craft Adwaita-style icons icons for third-party apps, tools, and services, bringing them into the visual fold to effect a more consistent, unified look across the system.
Or to let the folks behind MoreWaita explain: “The purpose of MoreWaita is to add to Adwaita, not modify it, and to do roughly what Breeze does for KDE. This theme does not override any Adwaita icons, nor any Gnome Circle apps icons, nor icons that generally fit into the Adwaita paradigm (like Transmission GTK).”