I own 3 collies and have been around hundreds more. (My wife shows them and trains them). Female collies, especially rough collies like Rev, tend to be naturally a bit shy or standoffish when they meet new people. They don't naturally trust new people. The females are also quite a bit more high strung than the males. On the other hand, they are very good with children and are very tolerant of harassment and handling for the most part. Collies are herding dogs, so they bark a lot. It is part of what they are bred for. They also chase and nip, which are more herding instincts. They come in 4 colors and 2 coats: Rough or long coat, like Rev, and Smooth or short coat. The colores are sable (like rev), blue merle, Tricolor, and white.
My collies..(all males):
The tricolor on the right looks a bit like the original rev.