I see many people are making their own custom display icons, in a week I will display a set here that is free for anyone to use including custom colors for any lines. If you have your own work submit them here as well for everyone to use.
To apply an icon to your display : Right click the picture, and click "Save As". Save it to an area on your computer where you can remember it. Then go to your account settings and upload the icon to your account and click "Save Profile Changes".