Sasha is not black
She's a white south African.
http://desmond.yfrog.com/Himg614/scaled.php?tn=0&server=614&filename=9a1vn.jpg&xsize=640&ysize=640
http://prettylittleliars.alloyentertainment.com/wp-content/blogs.dir/4/files/pll-stars-and-their-real-life-moms/sasha-pieterse-and-her-mom.jpg