A film revisiting the birth of the People's Republic of China will feature rare color footage of the founding ceremony held in Tian'anmen Square on Oct 1, 1949.

The movie, Mao Zedong 1949, will hit domestic theaters on Sept 20.

The cast comprises five veteran actors best known for playing political leaders in movies and TV dramas. And among them are actors Tang Guoqiang and Liu Jin, respectively playing Chairman Mao Zedong and Premier Zhou En'lai.

A highlight: the founding ceremony sequences near the end of the film is restored color footage that the crew purchased from Russia, says executive producer and director Huang Jianxin in a recent interview.

The ceremony where Chairman Mao officially announced the founding of the People's Republic China to the world had 300,000 people in Tian'anmen Square.

A number of films and TV dramas as well as documentaries feature the historic moment, but all of them are in black and white, as this is the only such remaining old footage in China.

Speaking about how he laid his hands on the footage, Huang says he happened to hear that a person has watched the color clip on his smartphone, so he assigned two teams to go to Russia to find the four-minute footage that was shot by former Soviet Union photographers. The footage was restored by a Chinese company, which transformed it into 4K ultra high-definition version.

The film was shot on a tight schedule of 67 days when usually a feature-length film is shot over three months, says Huang, who adds that the film is a "a miracle project".