Writer, producer, and director Wes Anderson chose to have the actors and actresses record their dialogue outside of a studio and on-location to increase the naturalness: "We went out in a forest, went in an attic, went in a stable, we went underground for some things. There was a great spontaneity in the recordings because of that."
The color scheme of this movie is primarily autumnal (yellows, oranges, and browns) with virtually no green and blue. However, Kristofferson's (Eric Chase Anderson's) blue-colored wardrobe was intentional, as it emphasized his being a visiting outsider.
CGI was only used in one scene, the flooding of the flint mine.
When Mr. Fox (George Clooney) and Kylie (Wallace Wolodarsky) are in Fox's study going over the plans for the first heist, Fox is sitting in a large armchair with a board on the armrests that he is using as a table for his microphone. This is exactly how Roald Dahl used to write his stories based on old photographs.
Roald Dahl's "Fantastic Mr. Fox" was the first book that writer, producer, and director Wes Anderson owned. His mother, Texas Ann Burroughs, bought it for him at the St. Francis book fair in Austin, Texas when he was about seven years old. Anderson has kept this same copy on his bookshelf ever since.