I read an interview with director Guillermo Del Toro (mimic, Blade II) and he said a couple of nice things:
- The plot is basically "Seed of Destruction", the first Hellboy series, except that it focuses more on Hellboy's relationship with Prof. Broom (his adoptive father, played by John Hurt) and offers an explanation to the Right Hand of Doom (the hand, not the series).
- Practically the only red things in the movie are Hellboy and the Nazi flags.