Requires iOS 6 or 7.
MagicBadges makes it easy to change the badges‘ position,size and color,use pictures(keeping their orginal color scheme) you like to replace default badge if you're bored with it,in the same way Zeppelin to Carrier Logos,or Alkaline to Battery Icons.
put badge background pictures(png format, size of 50×50 is perferred) into
/Library/Application Support/MagicBadges then they can be set as badge background from MagicBadges Settings' badge list page.
Configure in Settings app.
See larger Screenshots below..