I was referring to gulf coast box turtles, Terrapene carolina major. The coloration is very standard for males of this subspecies found in the panhandle region of Florida. They are not Florida box turtles, but Florida is part of their range.

http://www.painetworks.com/photos/fj/fj0947.JPG

http://farm1.static.flickr.com/129/321881686_6f218115bc.jpg

But, only genetic analysis can tell you for sure if your turtle is truly some type of unique morphology or an escaped pet.