The colours, i think, are to do either with their personality or their hair / skin colour. For example, Jacob Blacks wolf colour is a brownish colour, which is the colour of his skin. Sam, who I believe we saw at La Push Beach in the movie, I think his colour was black, which is the colour of his hair. Seth Clearwater was Sandy coloured, I always thought that was his hair but i may be wrong, and Leah is silver or grey, i think that ones personality.
No, but they are ferocious fighters.
They are real wolves then they use the computer to make them bigger - Team Jacob.
Computer anamation
no it has sparkling wolves
imprinting
there is not specific meaning for the color of their fur. just individuality
Mostly grey, sometimes a rusty color red.
they teach you hidden skills
The complete predicate is "At twilight ... appear from their resting spots". The initial prepositional phrase, "at twilight" is a part of predicate because it modifies the verb "appear" by describing the time of the appearance. It does not modify the subject of the sentence, "wolves" themselves.
There are gray wolves, red wolves, and white wolves(To my knowledge). There might be more colors though.
imprint
Bella Swan refers to the werewolves as "furry protectors" in the Twilight series.