Change application icon in taskbar

I dislike the default icon for the Geany text edidtor, so I changed it in the .desktop file. Now, when I open my applications menu (jgmenu), or when I add Geany to the tint2 panel, the new icon appears as I want it. Great.

However, when I launch Geany using either of these two starting points, the icon that appears in the list of active apps in the panel remains the stock Geany icon. How can I change that icon to use my preferred icon?

https://i.stack.imgur.com/vy2QW.png

The desktop icon is defined in the .desktop file. The icon from the running app is usually defined by the app itself. How the user could change that I have no clue.

I do not know but I think you would have to edit Geany for that. I am no expert on this though. X E.