Here is a Firefox icon I did for Safari feel free to use it,

How to install

1. Download an SFTP client i.e FileZilla
2. SSH into the device
3. Place all icons to /private/var/stash/Applications/MobileSafari.app
4. Set file permissions on all icons to 775
5. Respring the device.
6. and the icon should of changed

Any issues feel free to message me on
@ilimpwalk

Enjoy

-icon-2x.pngName:  icon-72.png
Views: 278
Size:  11.3 KBName:  Icon-Small@2x.png
Views: 277
Size:  8.1 KBName:  Icon-Small-50.png
Views: 276
Size:  6.5 KB