To be more clear, it's not necessarily the actual "stand your ground" law so much as the mindset behind it: If you feel the slightest bit threatened, even if the individual isn't brandishing a weapon or attacking you, you're justified in using deadly force against them. There have been a frightening number of cases where unarmed black people -- particularly black men -- were killed (often by police) in the US, yet the courts found that there was sufficient grounds to dismiss or reduce charges based on the shooters claiming the individual "looked suspicious", "looked like a thug", and so on. As individual cases, it's impossible to prove that race is a factor, but once a pattern starts to form... well, if becomes obvious that looking "suspicious" and "like a thug" frequently involves being black.
It may not be intentional on the part of the court or even the shooter (all too often, people make assumptions based on race without being aware that they're doing it), but extremely broad definitions of self-defence make the world a much more dangerous place for minorities, and allow too many bigots to get away with barely a slap on the wrist. Guy just claims that the person made them feel threatened, and presto, no major repercussions -- or, in other words, a subtler version of the gay panic defence, but for bigots of all stripes.
