Producers are readying to release a coloured version of Indian cinema's biggest blockbuster of all time, K. Asif's Mughal-e-Azam, on Diwali, Nov 12.

It will be the first time that a coloured and restored version of a classic will hit the screens. Also for the first time, a digitally re-mastered version of the film's original sound track will be released.

The epic star-crossed love story of a young Prince Shahjahan and the poor Anarkali, starring the legendary Prithviraj Kapoor, the thespian Dilip Kumar and the gorgeous Madhubala, first hit the screens in 1960 after almost nine years in the making.

It generated unprecedented interest, with an estimated 100,000 people gathering at Maratha Mandir in Mumbai, where the movie was released, to make advance bookings.

The film also created a rage in Pakistan and several other parts of the world, eventually being recognised as an all-time classic.

"It is a matter of immense pride for us to showcase Hindi cinema's greatest epic in colour," said Deepesh Salgia, the project director of the coloured version on behalf of producers Sterling Investment Corporation Ltd.

"It was K. Asif's unfinished dream to see Mughal-e-Azam in colour, which is one of the biggest reasons why we undertook the project." The colourisation was "the most complex" such project undertaken because of the exquisite clothing and the ornate jewellery used in the movie, according to officials of the Indian Academy of Arts and Animation (IAAA), which worked on the project.

"The colourisation is done to enhance the viewing pleasure by maintaining the characters and the aesthetics of the film. But it has taken almost one and a half years to develop the technology and another 10 months to complete the process," said Rajid Dwivedi, the technical director of IAAA.

IAAA created and customised a software that accepts only those colours which match the grey shades of the original, and incorporated features for a 35 mm release.

The restoration process included digitising the 300,000 frames of the film at 2K resolutions.

The producers involved the film's original music composer Naushad in the digitisation of its track.

As a result, the audience will get to enjoy the voices of the legendary Mohammed Rafi and Shamshad Begum, along with a young Lata Mangeshkar, for the first time in a Dolby Surround system.