One afternoon in late April, the artist Carmen Herrera was sitting in her apartment and studio a few blocks north of Union Square recalling the frequent visits she would make to the Whitney Museum of Art some 70 years ago, when it was located in Greenwich Village. “It was empty!” she said. “Nobody went to museums. It was incredible. And now, you go to a museum, you want to look at something and hundreds of people are in front of you.”

Herrera shared this with good-natured exasperation, almost laughing as she complained. She turned 100 this past Sunday, and seems well past the age of worrying. Plus it would not quite be fair to be too upset about the crowds at museums, since the throngs that are filling one of them at the moment, the Whitney’s new home in the Meatpacking District, are now seeing her work, after years of obscurity—a large painting she made in 1959 that has a short green isosceles triangle that stretches across the middle of a white canvas. The museum acquired it just last year.

Carmen Herrera, Blanco y Verde, 1959. WHITNEY MUSEUM OF AMERICAN ART

It is a stunning painting, and it is hung in perhaps the most beautiful and tranquil room in the new museum, alongside pieces by well-established giants like Frank Stella, John McLaughlin, Ellsworth Kelly, and Agnes Martin. The work is titled Blanco y Verde, a straightforward name that underscores Herrera’s remarkable achievement: an art of crisp, clear straight lines, of pure color and pure shape. Her paintings are cut to their bare minimum, but it would be wrong to describe them as sparse or restrained. Their solid colors are arranged so that they teem with energy, whether effervescent (as in a bright orange rectangular diptych from 2007) or subtle, like that 55-year-old white and green number.

In recent days Herrera had been having trouble hearing in one ear, and so her longtime friend, Tony Bechara, a voluble artist, sometimes helped her to understand my questions, speaking more loudly than me or translating them into Spanish, which she first spoke growing up in Havana. Nevertheless, she was quick with her quips. “Men!” she exclaimed, when Bechara spoke too much about her work. “We can’t live without them, and we cannot live with them.”

Carmen Herrera, Untitled, 2007. COURTESY THE ARTIST AND LISSON GALLERY

Herrera’s father was a newspaper editor, her mother a reporter. Growing up in Havana, she took art classes, but she studied to be an architect, quitting that path in the late 1930s when she married Jesse Loewenthal, a school teacher who died in 2000 at the age of 98. (By that point she had still not sold a single painting.) Around the time of her marriage she began painting in earnest.

Her first great inspiration was the Cuban artist Amelia Peláez, Herrera told me. “I admired her so much. I liked what she was doing. It was the first thing I really liked. I heard her and I asked questions, and she was terrific.”

The couple moved to New York, and Herrera studied at the Art Students League. “It was all women, and I hate to say it,” she said, shaking her head, “but we were like cats—fighting.” She recalled that one of her teachers, Fredo Sides, told one of her friends, “What is she doing here? Why doesn’t she go home and begin painting, think about whether she wants to be a painter or not? I think she’s very good, she better get out of here.” And so, “Thank you!” she said, “And I left.”

Carmen Herrera, Green Garden, 1959. COURTESY THE ARTIST AND LISSON GALLERY

She and Loewenthal moved to Paris after the war, where she quickly fell in with the abstract artists showing under the banner of the Salon des Réalités Nouvelles, and she developed an organic form of abstraction, with flowing, curving shapes. Europe seemed more receptive to her work, and the fact that it was made by a woman. By the mid-1950s the two were back in New York for good, and her work became sharper and more minimal. Barnett Newman, whose paintings perhaps most closely resemble hers, and his wife, Annalee, were neighbors. “We used to have breakfast every Sunday together.”

“I was very young, much younger than they were,” she said. “I was just listening. I knew very little English, but it was very interesting.” What did she learn from him? “Don’t be intimidated about anything,” she said. That was a useful lesson since, despite having occasional shows in the coming decades, nothing ever sold, a streak that ended only in 2004, when Bechara got a dealer interested for the first time, igniting a wave of support from the market and museums.

Midway through the interview, Bechara suggested a Scotch, which Herrera usually enjoys midday. He abstains.

“He’s very sober, he doesn’t drink,” she announced.

“I only drink at night.”

“I don’t care!” she said in a mock huff.

Carmen Herrera, Untitled, 1952. THE MUSEUM OF MODERN ART

Drink in hand, the stories kept coming. Filipino artist Alfonso A. Ossorio once lived below the apartment we were sitting in—Herrera has been in it for half a century—and had apparently wanted the space for himself. He would telephone occasionally and declare, “You better get out of there, because I’m going to kill you.”

And sitting with Jean Genet in Paris one day, an American woman approached, and attempted to flatter the writer, Herrera recalled. “She said, ‘Oh, I love your work,’ and this and that. And he said, ‘Oh, you too are a pederast?’” Herrera laughed heartily. “He was a sweet man but also a funny man.”

At 100, Herrera has become someone whom newspapers regularly declare, as Proust sardonically put it, one of “the last representatives of a world to which no witness any longer exists.” Of course, it is actually true, and the art world is finally paying its proper respects. The Whitney is at work on a retrospective for next year, Lisson Gallery, which represents her, is planning a show for later this year, and Alison Klayman, who directed Ai Weiwei: Never Sorry, is making a documentary about her life.

Meanwhile, though, Herrera is continuing to work. She still draws when she feels well enough, sitting by her front window, sketching out ideas for new paintings, which she then has transferred to grid paper and has her assistant execute. An unfinished new painting was sitting in her studio, a green triangle filling half of it. She was thinking about what to do with it next.

I asked her where her ideas for her forms come from. “I have to have it in my head,” she said. “I do a drawing, and then I figure it out.”

“Once you think about it,” she said, with a bit of bravado, “it’s very easy.”

“Art of the City” is a weekly column by ARTnews co-executive editor Andrew Russeth.