I changed the icon for some applications by editing their .desktop item and specifying the new icon. This works, because the new icon is shown correctly in the whisker menu (in the list of favorite applications, for example).
However, when the application is open, the icon shown in the xfce panel (in the window buttons item) is still the old one. Is there a way to change it also there?
Best Answer
I think the only way is to change the "icon set", in XFCE it's under the
"Settings Manager" -> Appearance -> Icons
(I'm not sure how to create a new custom icon set though, that's probably answered in another question or website somewhere)
Or maybe I missed the icons that you want changed... the minimize - maximize - close buttons?
They can be chanced with other themes in the
"Settings Manager" -> "Window Manager" -> Style
Settings page (and you can re-arrange & pick the visible buttons too).