Around 100 different copies of Rose's outfit were made. This started out with soft summery colors, and as the movie progressed, this became grayer and eventually blood red. The change in the outfits were so subtle that this was barely noticeable.
This 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.
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 there. Centralia planted the seed for what developed into the cinematic version of the town of Silent Hill.
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, who was only supposed to appear at the beginning and the ending of the film, had his role expanded along with the character Thomas Gucci added and the script was approved.
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.
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).
Due to the nature of the Silent Hill film and the fact that Jodelle Ferland was only 10 years old at the time of filming, writer Roger Avary apologized to her parents should she have had any signs of mental trauma.
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."
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.
Silent Hill's college visited by Rose is called Midwich. Midwich is the fictional town of Village of the Damned (1960) and John Carpenter's 1995 remake, both based on the original novel "The Midwich Cuckoos" written by John Wyndham and published in 1957.
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).
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 Street. This 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.
In a nod to Silent Hill 3 (2003), the game's theme song performed by Mary Elizabeth McGlynn is used in the film's ending 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.
In the behind the scenes for the 2006 film, the actresses explained that the Pyramid Head outfit had no covering on the back, and that the actor's buttocks were exposed. This was done intentionally, although the reason why has never been explained.
Radha Mitchell was so impressed by 10-year-old actress Jodelle Ferland's handling of three different characters (Sharon Da Silva, Alessa Gillespie and Dark Alessa) that she decided that Jodelle was her new favorite actress.
It is notable that Dahlia is immune to the dangers of the Fog World and the Otherworld. This is because Dahlia is the mother of Alessa, who controls these worlds, and is still loved by her, or as Rose says, "Mother is God in the eyes of a child."
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 three and a half hours, the film was never shot with that length in mind.
Christophe Gans was irritated by Radha Mitchell's approach to acting, which typically involved her needing several shots before she could get into character. In the DVD commentary, Gans states that it was especially difficult to film scenes with Radha and co-star Laurie Holden (Cybil Bennett), due to their very different acting techniques.
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.
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.
Previously, Deborah Kara Unger had a close friendship with director Christophe Gans, whom she considered a mentor. Gans felt Deborah was perfect for the role of embattled mother Dahlia Gillespie, who appears at two different ages in the film. When he first approached Deborah for the role, he told her not to slap him, as he was sure she would be angered at being asked to portray a ragged old woman. Instead, Deborah was delighted by the character and quickly accepted the role.
Roberto Campanella has stated that the helmet he wore for the Red Pyramid costume weighed approximately twelve pounds on its own. He also could not see in front of him or to the side due to the triangular grates that compose each side of Red Pyramid's helmet; therefore, Roberto could only see his feet and anything directly below him.
Both director Christophe Gans and Deborah Kara Unger refer to Dahlia as "Cassandra Dahlia". This is a reference to the Greek story of Cassandra, who had the gift of foresight, but was cursed to be believed by no one (often called "Cassandra Truth). Similarly, Dahlia speaks the truth of the alternate reality and warns Rose of the decision she will eventually have to make, but her words are ignored by the cult, Rose and Cybil.
According to actress Laurie Holden, Cybil always wanted children, but due to her lifestyle, she was unable to have any. This could be referring to her busy, dangerous line of work preventing her from adequately raising a child, or it could allude to the possibility of Cybil being lesbian.
Although this is not the first film that Tanya Allen appeared in, having acted in indie films and television movies prior to this film, this is her first major motion picture that had a wide theatrical release.
The bus map that Rose follows to Midwich School ends at Bradbury Street. Ray Bradbury was an author well known for fantastic stories such as "Something Wicked This Way Comes", "The Martian Chronicles" and "The Illustrated Man".
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 three letters and four numbers (AAA 0000) and was registered after 2004 because Ohio license plates changed formats in 2004.
Given the vast number of mannequins and mannequin parts seen in her apartment, it is likely that Dahlia was a mannequin maker before the fire. Mannequins are a recurring element in both the games and movies, a mannequin creature even appears as an enemy in the sequel Silent Hill: Revelation 3D (2012).