(Claritza Jimenez/The Washington Post)

President Herbert Hoover is wearing a two-tone V-neck sweater, black pants and white shoes. A colleague is wearing knickers. The lanky interior secretary, Ray Lyman Wilbur, is there, along with Hoover aide Larry Richey.

It’s a pleasant morning outside the White House, and the normally dour, stiff-collar president is cutting loose with a medicine ball in a game of “bull in the ring” while an observer — probably his wife, Lou — films it in color.

It’s a remarkable, relaxing scene from 1929 or the early 1930s, at the advent of the Great Depression, and it may be the earliest color film of the White House grounds and of Hoover, the Herbert Hoover Presidential ­Library and Museum said Tuesday.

“It was like opening a door and going back in a time machine,” said Lynn Smith, the audiovisual archivist at the library museum who made the discovery.

The films, which for years were thought to be in black and white, are home movies shot for the most part by Hoover’s wife, according to Thomas F. Schwartz, director of the library-museum in West Branch, Iowa, where Hoover was born.

Lou Henry Hoover in the White House garden in this screengrab from newly discovered color footage found at the Herbert Hoover Presidential Library & Museum. (Herbert Hoover Presidential Library & Museum)

The movies include shots of White House gardens; clips of Alonzo Fields, who was chief butler at the White House for 20 years; and scenes of family dogs, Weegie and Pat, playing on the grounds.

There are scenes of the Washington Monument and, with a blimp overhead, the Lincoln Memorial, with period cars cruising by, and crowds cavorting on the White House lawn at Easter.

Hoover is also captured on a deep-sea fishing trip, where he lands a barracuda. The president’s fishing garb consists of a coat and tie and gray fedora.

“Hoover was caught once without a tie, fishing, and he was upset because he thought the dignity of the office required . . . some formality, even when fishing,” Schwartz said in a telephone interview Tuesday.

“If the public even has any impression of Hoover, it’s a dark one, because of the Depression,” Schwartz said.

Hoover, a Republican who was in office from 1929 to 1933, is widely seen as failing to stem the nation’s slide into the Great Depression of the 1930s. The shantytowns erected by the destitute in those days were known as Hoovervilles.

He is usually portrayed as a serious figure, with a puffy, square face and a head of slicked-back hair.

People “see him in black and white, and he looks like a grumpy old man,” Schwartz said. “Who would ever imagine this guy running around the White House lawn throwing a six-pound medicine ball.”

“What do these movies do?” he said. “They make him a flesh-and-blood individual.”

Hoover was filmed playing “bull in the ring,” in which one player tries to intercept a medicine ball that is being passed among a ring of other players.

But he wanted to make it more challenging, Schwartz said. So he created what came to be known as “Hooverball,” which is like volleyball played with a six-pound medicine ball.

“He’s the only president to have created a sport,” he said. In the clip, “you see the guy actually smiling,” Schwartz said. “He’s enjoying himself. . . . People don’t associate Hoover with laughter, relaxing, having a good time. It’s always this driven individual.”

The films are believed to have been shot on the short-lived ­Kodacolor-type film, Schwartz said in an essay about the find.

“Kodacolor was eventually replaced with the more popular Kodachrome film in 1935,” he wrote. “Given the expense of the film and its short existence, color home movies from this period are rare.”

“Rarer still are color movies showing the White House and other Washington, D.C., attractions making these perhaps the earliest color images of the White House grounds,” he wrote.

“For now, we think we’ve got the earliest,” Schwartz said in the interview. “If someone can prove us wrong, that’s fine. We’re happy with the discovery.”

Kodacolor was first released to the public in August 1928, and to the naked eye it looks like black-and-white film, except for some telltale lines on the film itself, he said. Hoover’s wife loved photography and had shot other footage in black and white.

She was an accomplished woman, Schwartz said.

“She was the first woman to enroll in the geology program at Stanford University,” he said. “She was the first woman to major in geology, period, in the country.”

She met Hoover at Stanford.

“He was a senior, she was a freshman,” Schwartz said. “They were kind of complete opposites. She was very athletic, very outgoing, very sociable. And he grew up with that Quaker reticence, and always was looking at his feet, and kind of grunted one- or two-word answers to questions. But they hit it off.”

Smith, the archivist, said that two years ago, she was doing a routine inventory of the 16-millimeter palm-size film reels, which were given to the library-museum by the Hoover family in the 1990s and are kept in cool storage. The library is overseen by the National Archives.

The films said “Kodacolor” on them, but the strips looked black and white to the eye, except for strange lines on the frames. “What’s going on here?” she said she thought.

She did some research and discovered that the lines were devices that helped the film come out in color when run through a specially filtered projector.

Unable to replicate the long-vanished technology, she got a $5,600 grant from the National Film Preservation Foundation, in San Francisco, to have seven reels preserved, digitized and copied.

She said she began to wonder: “Hey, these could be the first ­extant White House films in color, of any way shape or form. Wow. That doesn’t happen every day.”

She saw the final result last December and thought: “How amazing.”