If I remember correctly you’re using Papirus as the icon theme in your system. If this is true, you have to replace the file /usr/share/icons/Papirus/32x32/apps/cs-desktop.svg with the icon you prefer.
If you want to use a green/teal icon in your panel for this action, you can copy the file /usr/share/icons/Papirus-Dark-Maia/32x32/places/user-teal-desktop.svg somewhere in your home directory, rename it to cs-dekstop.svg and copy it in the directory /usr/share/icons/Papirus/32x32/apps/.
To see the difference you can restart the panel using xfce4-panel -r in a terminal window.
The file you are looking for is in /usr/share/xfce4/panel/plugins/showdesktop.desktop
and change the line Icon=org.xfce.panel.showdesktop
to something that suits your taste about that icon.
The org.xfce.panel.showdesktop are symlinks to what Bill mentioned above about cs-dekstop.svg icon … so you could replace with Icon=user-teal-desktop
Since is part of xfce4-panel package, it will be overwritten every time that package is updated. The same will happen if you replace the icon when the icon theme is updated.
Hi Bill,
You are right I am using Papirus, I used your method and restarted xfce-panel but the icon is still blue. I also logged in and out just in case.
A little video showing what I did:
bogdancovaciu, I also used your method and changed icon=org.xfce.panel.desktop to cs-desktop and restart xfce-panel. But still no change
Has it got anythithing to do with me making the panel smaller in the past?
Try this in your ~/.config/gtk-3.0/gtk.css file (if it doesn’t exist create it)
#showdesktop-10 image {opacity:0;} /* the number after showdesktop may differ on your system. Go to the Panel preferences > Items tab and hover your mouse over the item to get the correct number */
#showdesktop-10 button {
background-image:url('/usr/share/icons/Papirus/22x22/places/folder-green-desktop.svg');
background-size:61%; /* or adjust value till it looks sharp */
background-position:50% 50%;
background-repeat:no-repeat;
}