Ability Over Appearance: Lucy in the book is blonde. Georgie Henley is brunette but captures Lucy perfectly. The two boys' hair colours are never mentioned but illustrations have Peter brunet and Edmund blond - this is inverted in the film. The only Pevensie to keep the same hair colour is Susan.
Jadis is also commonly depicted with black hair - and she was going to be in this. However they changed it to blonde so as not to make her look too gothic. Tilda Swinton received unanimous critical praise for her performance
Enforced Method Acting: In the Walden Media film, Tilda Swinton (White Witch) flirted with Skandar Keyes (Edmund) to make him feel more uneasy for their scenes together.
The entire film was shot in near-chronological order - so that the characters' emotional growth would be reflected by the physical growth of the actors.
Executive Meddling: Lewis was dead when the books were re-ordered. He had no intentions of re-ordering the story himself, his only public expression on the order of the books being a simple letter to a child telling him to read them in whatever order he thought best.