The favicon of Magento is a blue speech bubble with
MA, and the favicon of Martial Arts also is a blue speech bubble with
Note: I'm talking about the 16x16 favicons, not about the icons on the site list, which are different.
Another note: perhaps you are not able to reproduce it (Shadow Wizard could not), but then you'll still see it on the site list (screenshot provided by Shadow):
Can they please have different icons?