I'm running Kubuntu 18.04. There's an icon in the lower left corner that brings up the application list (by default a big K). I did something that changed it, but I don't know what. Where in the system settings is it specified?
72 Answers
Right click on the icon, and pick "Application Launcher Settings."
Then click on the Icon button and select "Choose". Navigate to the icon you want and use that. It looks like this:
The image looks a little funny because I used DistroTest to grab the screenshot. However, that's 18.04 and that's how you change the icon for the application launcher/menu.
You should be able to make changes with the K Menu Editor. If you can't find it, open Konsole and type kmenuedit 👍🏻