PARIS — Daylight is again streaming onto Claude Monet's celebrated water lilies in a Paris museum where eight of the color-drenched canvases are returning to public view.

The Orangerie Museum will reopen to the public May 17 after a painstaking six-year renovation, paying tribute to impressionists' love of light by installing a giant skylight and making the building again resemble a greenhouse — its original use.

French Culture Ministry officials postponed the opening "for security reasons and to optimize the welcome of the public," Anne Samson, head of the public relations firm handling the reopening, said Wednesday.

Workers tore up the low, drab ceiling that had sliced the museum horizontally, and a vast skylight now opens up above the impressionist masterpieces for the first time in more than four decades.

Tucked into the Tuileries gardens, the stone structure once sheltered delicate orange trees in the winter before becoming home to Monet's mammoth water-lily artworks.

"The most important part of our work was to give the light back to the water lilies," Olivier Brochet, one of the architects on the $31 million project, told The Associated Press.

"These paintings are so close to nature, weather and time that it was a crime to block out the sunlight," said Brochet, referring to a 1960 expansion that slapped a second story onto the museum, above the gallery housing the lilies, depriving them of light.

On sunny days, a new glass roof floods the water-lily room with natural light; a freshly installed system of overhead spotlights will help illuminate the mammoth canvases on Paris' many cloudy days.

For the last three decades of Monet's life, his main subject was his front yard in the small French town of Giverny, with its lily-filled pond, Japanese bridge and weeping willows. He painted hundreds of works of water lilies and donated eight large-scale canvases to the French people at the end of World War I.

Monet helped draw up plans to transform the Orangerie — which was used to store equipment and house soldiers during World War I — from a 19th-century greenhouse into a gallery. He died a year before the exhibit opened in 1927.

The museum, which still had a glass ceiling then, became one of the pilgrimage sites for impressionist painting. French painter Andre Masson praised it in a widely cited 1952 article as the "Sistine Chapel of Impressionism."

But to make room for a major donation of paintings in the 1960s, architects added on a second floor, cutting the space in two horizontally with a concrete slab. Renovators have torn down the offending addition and moved the donated collection, which features paintings by Paul Cezanne and Pablo Picasso, to a new annex — also illuminated with natural light.

During renovations, most of the collection went on the road as part of a traveling exhibition that visited museums in Fort Worth, Texas; Sydney, Australia; and Tokyo. Earnings from the tour financed a quarter of the renovation costs.

Monet's water lilies, however, could not travel with the rest of the collection. Built into the walls of the Orangerie, the paintings remained in place — and behind protective boxes — during the renovation, which ran two years beyond schedule.

One of the reasons for the delay was the discovery of the remains of a 16th-century wall, architect Brochet said. Part of the wall is on display inside the museum.