- Video report by ITV News Correspondent Dan Hewitt
One of Big Ben's newly restored clock dials has been unveiled after more than a year of work to reveal a face with blue hands and numbers - not black.
The North Dial, which faces over Whitehall and the Embankment, is now fully visible after the surrounding scaffolding was removed and some tourists have been left surprised at the new colour.
A clock face of Big Ben is one of the world's most iconic images and anyone with a photograph of the North Dial will most likely have seen black not blue when taking their snap - unless it was before the 1930s.
Before then the Elizabeth clock tower, which was completed in 1859 after being designed by architect Charles Barry and Augustus Welby Pugin, had ironwork painted Prussian blue with gold frames filled with white glass.
Before restoration of the Elizabeth Tower began a consultation with Historic England was carried out which involved researching the original drawings and taking samples of remaining layers of old paint for close examination.
Adam Watrobski, Parliament’s principal architect said: "As part of the major repair and conservation of the Elizabeth Tower, we have carried out extensive research into the original decorative scheme for the clock faces and the adjacent areas.
"Using historic paint analysis and references including Barry’s original design watercolour, contemporary illustrations and archival photographs, we have recreated the original colour scheme."
He added: "The dials and clock hands are Prussian blue and gold and the adjacent areas make use of the red, white and blue colours of the Union flag, along with the detail colours used for heraldic shields for each part of the United Kingdom."
Conservative Dame Caroline Spelman, chairwoman of the Joint Committee, said the restoration and renewal programme provided a "magnificent opportunity to deliver a Parliament that is more open and accessible and meets the needs of the 21st century and beyond".
The total overall cost of the project is now estimated at £61m as opposed to the £29m estimated in spring 2016 before work began in 2017.
The programme of works on the 160-year-old tower is expected to complete by 2021.