Gianluigi Colalucci, led the restoration of Sistine Chapel frescoes

“Until you have seen the Sistine Chapel,” the German poet Johann Wolfgang von Goethe wrote in “Italian Journey,” an account of his travels across Italy in the 1780s, “you can have no adequate conception of what man is capable of accomplishing.”

“One hears and reads of so many great and worthy people, but here,” Goethe continued, marveling at the frescoes adorning the ceiling of the chapel at the heart of the Vatican, “above one’s head and before one’s eyes, is living evidence of what one man has done.”

That man was Michelangelo Buonarroti, the Italian artist who in 1508, at age 33, began painting the Sistine ceiling on the commission of Pope Julius II. Along with the depiction of the Last Judgment, which Michelangelo added to the chapel’s altar wall nearly three decades later, the ceiling is a masterpiece of Renaissance art.

But for generations — until the restoration effort undertaken in 1980 by Gianluigi Colalucci, chief conservator of the Vatican Museums — visitors who entered the Sistine Chapel saw not only the living evidence of what Michelangelo had achieved, but also living evidence of the ravages that time had wreaked on his art.

A dusky hue had come to hang over the chapel, darkening Michelangelo’s representations of God giving life to Adam and Christ dispatching the saved and the condemned to their fates. The darkness, scholars determined, was the result of the accretion of dust and dirt, fungi, varnishes and wine used in primitive restorations, and soot from candles lit during papal conclaves and other religious observances.

To paint the Sistine ceiling, Michelangelo labored atop a towering scaffolding, his neck craned skyward and paint dripping onto his face. In an enterprise that captivated the international art world, Colalucci assumed the same position for the delicate task of cleansing the chapel of the layers of filth that had accumulated during the intervening centuries.

It took Michelangelo four years to paint the Sistine ceiling and 10 for Colalucci and his small team of restorers to clean it, not including the four years they then spent on “The Last Judgment.”

The restoration, although deeply controversial at the time, is regarded today as one of the most consequential undertakings in art history — an artistic resurrection that liberated Michelangelo’s work from a shroud of grime and allowed millions of visitors to experience the full palette of his colors as they had not been seen since the 16th century.

“The cleaning basically gave us a new Michelangelo,” Carmen C. Bambach, a curator at the Metropolitan Museum of Art who witnessed the restoration process, said in an interview, describing Colalucci’s work as “a gift that is of lasting, monumental contribution.”

Colalucci died March 29 at a clinic in Rome, according to his wife, Daniela Bartoletti Colalucci, who said that he had heart ailments. He was 91.

One of the most experienced art conservators in Italy, Colalucci was hired by the Vatican in 1960. He became chief restorer in 1979, the year before the work on the Sistine Chapel began, and retired from the Vatican Museums in 1995, the year after it was concluded.

A New York Times reporter once noted that by the end of his efforts in the chapel, Colalucci’s brown hair had turned white.

Some artists and art historians feared that any hand laid to Michelangelo’s frescoes could subject the Sistine Chapel to ruinous harm. In 1987, a group of artists including Robert Motherwell, George Segal, Robert Rauschenberg, Christo and Andy Warhol petitioned Pope John Paul II to order a “precautionary” pause in the restoration.

James Beck of Columbia University, the most prominent art historian to oppose the restoration, denounced it as an “artistic Chernobyl,” while another preservationist accused Colalucci of “cleaning Michelangelo like a rug.” But by the end of the process, any fears had been allayed.

Colalucci, who displayed a seemingly constant equanimity under scrutiny, once commented that “you don’t do this kind of work if you’re the nervous sort.” Acknowledging his critics’ reservations, he observed that dirt had befouled the frescoes for so long, even experts struggled to imagine the chapel, or Michelangelo’s capabilities as a colorist, in a different light.

Generations of art scholars “preferred a brooding Michelangelo, the painter of mysterious figures hidden in the shadows, and concealed from us in their secrets,” Colalucci told the Wall Street Journal.