Blueman is a GTK+ Bluetooth Manager
Note to maintainers: We found that the Adwaita Icon Theme does not serve applications in general anymore and specifically dropped most non-symbolic icons in version 44. blueman with just Adwaita Icon Theme will show missing fullcolor icons at least for devices. It seems like we are left with shipping assets for all icon names that we use (or that BlueZ provides us) and will provide a solution in a later version. You can jump in at #2312. In the meantime, make sure that your packages depend on some proper icons themes. UPDATE: Adwaita Icon Theme 46.2 added inheritance of its legacy theme, so that all icons are available again.