Around 100 different copies of Rose's outfit were made. It started out with soft summery colors and as the movie progressed it became grayer and eventually blood red. The change in the outfits were so subtle that it was barely noticeable.
It took director Christophe Gans five years to obtain the rights to make the film. He was given the rights after he sent Konami a video of an interview describing how much Silent Hill meant to him. Along with the interview, he sent scenes that he filmed on his own dollar cut up and overlayed with music from the games.
In the original script, there were only female characters. After submitting this, the script was returned to Christophe Gans with a memo saying "there are no men!". Sean Bean's character was added and the script was approved.
Centralia, Pennsylvania was the inspiration for the movie adaptation of the game Silent Hill. In researching the different elements of Silent Hill, screenwriter Roger Avary came across the town of Centralia, Pennsylvania, an almost abandoned town with a 40 year old coal fire burning underneath it. Centralia planted the seed for what developed into the cinematic version of the town of Silent Hill.
In the beginning of the film, when Rose is running frantically trying to find Sharon, She runs through a tunnel. On the tunnel walls is graffiti that says the name "Cheryl". Cheryl is the original name of Sharon from the video game.
In the film, Silent Hill is a desolate ghost town that had been abandoned because of a dangerous 30-year-old coal fire burning in the mines under the town. Screenwriter Roger Avary used a real-life town as the inspiration for Silent Hill: Centralia, Pennsylvania. Centralia is almost completely deserted due to a mine fire burning right under the community for 40 years. Avary saw what Centralia had become, as well as its history, and decided to use its past as the basis for Silent Hill.
One of the stores visible in the movie version of Silent Hill is called "M.T. Rooms" - An inside joke referring to the fact that in both the film and the games, most of the structures are mere facades with nothing behind them (Empty Rooms).
Dancer/choreographer Roberto Campanella not only played as creatures Pyramid Head, the tortured Janitor, and Colin (the janitor from 30 years ago), he was also movement coordinator for all of the creatures and oversaw how they performed the movements for their respective characters (i.e. Grey Child, Dark Nurses and Armless Man).
In the final scene, when the congregation has gathered, a phrase written in Latin is visible around the ceiling of the main chamber. It reads, "Domine Deus Omnipotens in Cuius Manu Omnis Victoria Consistit..." Translated this is "O Lord God Almighty, in Whose Hand all Victory Rests..." This is a portion of an old English Prayer from the Pre-Conquest period. The rest may read "... and all war is destroyed, grant me that Thy hand may strengthen my heart so I may fight well and act courageously so my enemies may fall before my sight."
In a nod to Silent Hill 3, the game's theme song performed by Mary Elizabeth McGlynn is used in the film's end credits. Another song from the game plays in a scene involving Rose and Sharon Da Silva in their car playing on the radio, the song also played on a car radio during a cut-scene in Silent Hill 3.
Filming in Brantford, Ontario, Canada lasted four days. The decaying downtown strip that was used for most of the film is a section of Colbourne St. It was picked as such because not many modifications were needed as that area of the downtown was already in a state of decay (but has since been cleaned up considerably) and consisted mostly of abandoned buildings that could be 'dressed' easily for filming.
The version we see in theaters is the one director Christophe Gans wanted us to see. He said in an interview that the studio executives loved his version, and he was never asked to cut down his film length. Although the initial script of the film was expected to be 3 and a half hours, the film was never shot with that length in mind.
The prayers recited by Christabella and the citizens of Silent Hill within the church in their effort to keep the dark side of Alessa at bay are actually lines from Revelation, a book in the New Testament of the Bible.
Jodelle Ferland (Alessa) appeared as little Carrie White in Carrie (2002). The character of Alessa from the video game pays homage to (and is likely inspired by) Stephen King's novel "Carrie". A poster of Carrie (1976) can be seen in Silent Hill (1999).
Although Roger Avary is the only writer credited in the film, the original treatment was written by Nicolas Boukhrief and Christophe Gans, and all versions of the script were written in tandem between Gans, Avary, and Boukhrief.
Christophe Gans' wanted all of the film's music to come from the games, which were composed by Akira Yamaoka. However, the film's production contract required that a Canadian composer be involved. To remedy this, Danna was hired to remix Yamaoka's tracks.
When Rose is arrested the camera pans behind the Jeep showing the Ohio license plate "C3J 46E5" with a county code sticker "75" in the bottom left corner indicating Shelby County, Ohio. The license plate is a custom plate as in that standard issue plates are formatted as 3 letters and 4 numbers (AAA 0000) and was registered after 2004 because Ohio license plates changed formats in 2004.