Sunny in Manhattan

“I was born and raised in New Jersey, and it’s a very different sensibility,” said Ms. Littman, who has always been attracted to the buzz of the city.

When I was a teenager, I’d take the train and come into New York. I was an adopted New Yorker for a very long time.

Now, Ms. Littman, a 69-year-old mother of three and grandmother of six, has a sunny new 2,400-square-foot Chelsea penthouse to call her own. “This is my escape,” she said.

Never mind that her husband, Leonard, 75, spends most of his time in New Jersey. “My husband is a Jersey boy through and through — he should be singing on Broadway,” she said. “He’s lived on the same street for 70 years.”

They also have a beach house in Deal, N.J., which often serves as his refuge, Mr. Littman said. “I’m always much more comfortable in New Jersey,” he said. “The beach is definitely more my thing, and I love the grass and trees.”

When he wants to visit his wife in the city, he makes an appointment. “It’s not that bad,” Ms. Littman said. “But he’ll usually say something like, ‘I’d like to come in and have lunch.’ It’s kind of a joke between us.”

The Littmans bought the apartment for just under $4 million in 2009, and Ms. Littman spent about two years and $190,000 transforming it into the minimalist space of her dreams, in collaboration with Robert D. Henry, a New York architect.

And while many people her age might prefer a home that’s warm and cozy, her apartment borders on the austere. “Comfort has not been my strong suit,” said Ms. Littman, who teaches interior and furniture design at Kean University, the New Jersey Institute of Technology and the School of Continuing and Professional Studies at N.Y.U. Her primary concern was creating a bright, fresh, modern space where purity of line prevailed.

But then she has never seen age as an impediment. Ms. Littman met Mr. Henry in her early 50s, after deciding to pursue a master’s degree in architecture at the New Jersey Institute of Technology, where he was an instructor. And now, as then, one of his primary roles has been to critique her design decisions, including her tendency to avoid color.

“With Barb, it’s generally gray, white and black: that’s her thing,” Mr. Henry said. “I love her beach house, because it’s the only dark house out there. But here, we said, ‘Let’s bring a little color into your life.’ ”

And right from the home’s entrance, it’s clear he was successful in persuading her — one long wall, running the length of the apartment, is a brilliant shade of yellow. But it did involve some trial and error. “We went through seven or eight different yellows before we found the right one,” he said.

“I wouldn’t have done it on my own,” Ms. Littman said. Nevertheless, she added, “I get great pleasure when I come in and look at it. It’s a strong statement, but calm at the same time.”

Underfoot, a strip of white crystallized glass leads the way to an open staircase that climbs to the roof. It also creates something of a catwalk for the fashionable Ms. Littman.

The kitchen and living room —sparsely furnished with items from her furniture and sculpture collection, including pieces by Ettore Sottsass, Michele De Lucchi and Ron Arad — are on one side of the catwalk. The private quarters, including two bedrooms and an office, are on the other.

Renovated to reflect Ms. Littman’s tastes, the apartment is now “really my spot,” she said. “When I look out the window, I just love being part of the city. It’s the energy here that’s always been something for me.”