No, not "steven king dark" and I wouldn't take a pre-teen to see most of the movies based on his books. People forget these days, there are books and movies for kids and books and movies for adults (when I say adults, I don't just mean x-rated, but mature themes).
By the way, I'm shocked that nobody has jumped on Dahl for being a Satanist, since he did write The Witches.
Give them time.... they don't know what all to be outraged about yet ;~D