Real life painter Francesco Clemente created Finnegan Bell's artwork for the movie.
Alfonso Cuarón always use the green (he even auditioned green eyed girls for A Little Princess (1995)) as the main color of its movies. He uses red and orange (complimentary and opposite colors) to make some remarks.
In his book, "What Just Happened?", producer Art Linson reveals that the narration in the movie was written by David Mamet. It was done for free, on the condition that nobody ever find out he did it.
Ca d' Zan, a mansion in Sarasota, Fl, stood for Ms. Dismoor mansion. It once belonged to circus magnate John Ringling and his wife Mable.
In addition to co-writing, performing and producing the song "Siren" especially for this film, Tori Amos provided the vocalizations (wistling, breaths, etc.) that can be heard in the film's score.
While sharing the title with the 1861 Charles Dickens novel, it is only loosely based on it.