Change Admin Icon

Is it possible to change the icon that shows for Admin in Orca?

I've tried to upload a new icon (overwrite the old) but it seems that I'm not allowed to do that. I've tried changing permissions on the folders, and the file itself, but that is also not allowed.. I can change the permissions on the Orca folder, anything inside it.. not a chance..

any help would be appreciated.

Laz