Big Ben is to revert to its original Victorian colour scheme - featuring Cross of St George shields and dark blue dials and clock hands.
An artist's impression issued by the House of Commons Commission shows six shields with the red and white English national flag above the clock on the Elizabeth Tower.
Researchers examined the original drawings of the tower completed in 1859 and took samples of old paint.
It forms part of a £61m renovation.
The shields above each clock face are currently gold and black, while the metal work is painted black.
It is thought the colour scheme was adopted in the early 20th Century after the tower, designed by Charles Barry, had been blackened by decades of heavy air pollution.
Areas of black paint around the stonework on the outside of the clock face will be gilded and new white opalescent glass will also be installed as part of the repair to the tower which started in August 2017 and will last four years.
Liberal Democrat MP Tom Brake, spokesman for the House of Commons Commission, said: "The new colour scheme is not going to be dramatically different to what people see now. However it is restoring it back to what Charles Barry had in mind.
"Something that people will notice is a contrast between the clock face and the clock hands and the surrounding tower."
All four home nations are represented on the clock through shields featuring a rose, leek, shamrock and thistle.
Adam Watrobski, Parliament's principal architect, described the clock as the "crowning glory" of the restoration, saying it reinforced the "symbolism of the tower in its international representation of the United Kingdom".
He added: "Using historic paint analysis and references, including Barry's original design watercolour, contemporary illustrations and archival photographs, we have recreated the original colour scheme."
Big Ben basics
- The Great Bell forms part of the Great Clock in the Elizabeth Tower - commonly known as Big Ben
- It weighs 13.7 tonnes and the Elizabeth Tower stands 96m (315ft) tall
- Every hour it strikes an E note, and every 15 minutes four "quarter bells" chime
- To stop the chimes, the striking hammers will be locked until 2021
- The Elizabeth Tower is said to be the most photographed building in the UK