Lubuntu Legacy Icon Theme On Debian.
Lubuntu used to come with LXDE and they used the Box Theme. This came with all versions of Lubuntu before they switched to LXQT. Here is how you can get this theme. It works on all desktops including KDE and LXQT.
00:00 Intro
02:36 Download Icon Theme
03:32 How To Install
06:00 Icon Theme
09:00 Summary
The icons can be downloaded from here:
https://launchpad.net/ubuntu/bionic