The Louvre Museum in Paris has removed Winged Victory of Samothrace from public view for a year of restoration.
The statue of the Greek goddess Nike, created around 190BC, was installed in the 19th Century. It is seen as one of the museum's most iconic works.
Restorers want to highlight the original contrast between the pale marble statue and the darker blue-grey of its ship's prow support.
The headless statue's Paros marble has yellowed with time, officials said.
Winged Victory, by an unknown sculptor, was discovered in 1863 by a French diplomat, Charles Champoiseau, on the Greek island of Samothrace in the Aegean Sea.
The sculpture looms over the Daru staircase which leads Louvre visitors to the Mona Lisa.
The 4m euro ($5.27m; £3.4m) project comes three years after another Louvre masterpiece, the Venus de Milo, was restored.