"After much back-and-forth, on September 27, 1988, the National Film Preservation Act[28] became law. The Act created the National Film Preservation Board and it, together with the Librarian of Congress, curate the National Film Registry of “culturally, historically, or aesthetically significant”[29] films. Each year, twenty-five films are selected to be preserved in the National Film Board Collection at the Library of Congress. Outside experts and the public can recommend films for inclusion, and once a film is added, any version of the film that is “materially altered”[30] (such as colorized), needs to be labeled as such."
It's a Colorful Life: Colorizing Black and White Movies - HeinOnline