I am the only African American in my entire DPT program (among all 1st, 2nd, and 3rd year students).
So either there weren't any other African American applicants to my program, or they don't have a quota system to fill.
I can't honestly say whether being a person of color carries any weight, but I would say not to rely on it to get into PT school. It really comes down to the strength of your application (prerequisite grades, GRE, GPA, essay, extracurriculars, observation hours, etc.)