This icon is intended to give a graphic representation of what a PPA is. I could not find an icon that best represents a PPA, so I made one myself in GIMP 2.8 on Ubuntu.
This is a completely free image PPA Icon that you can download, post, and use for any purpose.
Image License: CC0 No Rights Reserved
You can copy, modify, distribute and perform the work, even for commercial purposes, all without asking permission, and at no cost. This image is completely free.