Regarding LOST GIRL, it should be noted that both "Hale" (black) and "Trick" (Little Person) are very regular as "semiregulars" go. They're both in almost every episode, often quite prominently. In fact, I was surprised to hear that "Trick" is considered a semiregular character; he strikes me as a fairly major character.
And HAVEN introduced a black character this last season, but, at the risk of being spoilery, he's unlikely to return next season . . . .