She's brown to me. Throughout the entire film (well when she appears) she's clearly brown. According to Paint, it does fall in the purple/blue section, but the color is saturated, giving it a more brown look. So I refer to her as being brown.
She does show some of her face. She's only in the movie very briefly. None of the shots are too up close, though.
And if they had left sharptooth out and turned it into "someone else" that would have ruined the scene. It wouldn't make sense at all to not mention him. If they had done it like that, then the scene just wouldn't work out. There's really no reason why they should not mention sharptooth. There's no reason why he should only be exclusive to the first movie and not get any mention in later films.
That would cause discontinuity, and that's not a good thing to have in a movie series.