Comment 2 for bug 1592480

I've tested in xfce4, and I can see why this bug maybe developed.

We've always set an icon. But for a while now, we've set the symbolic version of our icon (a standard icon alternative that is a one-color outline of an icon, with an adjustable color). It looks like many panels don't properly set the symbolic color to use on the icon (i.e. set a white icon for a dark panel or a dark icon for a white panel). *Possibly* because they can't and the GtkPlug infrastructure doesn't give them that option after all.

Anyway. I've reverted back to the full color icon (which is quite dark, but not entirely so). Smart panel implementations can still try and find the symbolic version themselves and use that in preference if they like.