A vividly hued Picasso portrait of longtime muse and partner Dora Maar that had remained out of view for more than eight decades sold at auction Friday for 27 million euros (about $31.3 million).

Painted in July 1943, “Bust of a Woman with a Flowered Hat (Dora Maar)” depicts Maar in a brightly colored floral hat. Maar, an artist and photographer herself, had been Picasso's partner and muse for about seven years, and the relationship was coming to a painful close. The work was purchased in 1944 and had not been on the market since, remaining in the family collection.

The painting was auctioned at the Drouot auction house, which called the reappearance of the work, part of Picasso’s “Woman in a Hat” series, "a moment of rare significance, revealing for the first time the full radiance of a work long kept secret.”

At a preview this week, Picasso specialist Agnes Sevestre-Barbé marveled at how vivid the portrait has remained.

“We have a painting that is exactly as it was when it left the studio,” she said. “It wasn’t varnished, which means we have all its raw material, all of it. It’s a painting where you can feel all the colors, the entire chromatic range."

“It’s a painting that speaks for itself,” she added. "You just have to look at it — it’s full of expression, and you can see all of Picasso’s genius.”

Previously, Sevestre-Barbé noted, the work had only been seen in a black-and-white photograph. “We couldn’t imagine from this photo that this painting was so colorful, so amazing, really.”

Auctioneer Christophe Lucien said before the sale that the work was of huge interest across the globe.

“It's being talked about in all the world capitals with a strong art market, from the United States to Asia, and of course through all the major European markets,” he said.