Ms. Kim’s other Broadway musicals included “Dancin’” (1978), “Tommy Tune Tonite!” (1992) and her last, “Victor, Victoria” (1995). She also worked on plays like Tom Stoppard’s “Jumpers” (1974), John Guare’s “Four Baboons Adoring the Sun” (1992) and a revival of “The Front Page” (1986).
Dance was an equally important aspect of her career. In that area, she became known for two significant design accomplishments. She was said to be the first to switch from heavy, woolly nylon to lightweight stretch fabrics for dancers’ costumes and to paint designs on those new fabrics, starting with Margo Sappington’s 1971 ballet “Weewis.” As Ms. Kim recalled, a Brooklyn paint dealer agreed to sell her his product only after she promised to get his niece, a dance student, a scholarship at the Joffrey Ballet.
She found her dance work liberating, she said, because unlike characters in theater, dancers did not have to look like “people operating in a real world,” no matter how fanciful. But she considered her designs for opera, like the “Turandot” she did for the Santa Fe Opera in 2005, the most interesting in her career.
Ms. Kim’s milieu was almost exclusively the stage. But she did win an Emmy Award in 1981 for the costume design of “San Francisco Ballet: The Tempest,” which appeared as part of PBS’s “Great Performances: Dance in America.”
She did only a handful of other screen projects: one movie (Francis Ford Coppola’s “Gardens of Stone,” a Vietnam War home front drama) and two television specials, all in 1987. “Maybe astrologically something was going on” that year, she said in an interview in 2009.
Ms. Kim received numerous design awards during her six-decade career, but one of the most cherished was the Coronet Culture Medal from the South Korean government, awarded to her in New York in 2008.
Wullah Mei Ok Kim was born on June 30, 1917, near Santa Ana, Calif., one of six children of Shoon Kwan Kim and the former Nora Koh, Korean immigrants who soon moved the family to Los Angeles, where they operated a grocery store.
Wullah (she Americanized the spelling of her first name later) showed an early aptitude for art. Because she also loved clothes, she hoped to become both a fashion illustrator and a painter.
After graduating from Belmont High School, she took art classes at Los Angeles City College. Then she continued her studies on scholarship at Chouinard Art Institute in Los Angeles, which later merged with another school to become CalArts, the California Institute of the Arts.
In 1942 she began what should have been her dream job, working as a fashion illustrator at the May Company department store. But within months, she left for Paramount Studios (a teacher had sent her portfolio there), where she became the assistant to the costumer Barbara Karinska. The two worked with Raoul Pène du Bois, who was designing most of the costumes for the Ginger Rogers film “Lady in the Dark” (1944).
In 1945, after working with Ms. Karinska and Mr. Pène du Bois on other films, Ms. Kim followed her mentors to New York. Later that year, “Are You With It?” became the first Broadway musical for which she assisted Mr. Pène du Bois.
California beckoned once more, and she went home to study at the Jepson Art Institute with the Italian painter and designer Rico Lebrun. When she returned to New York in 1950, her association with Mr. Pène du Bois continued. They worked together on some of the biggest Broadway hits of the decade, including “Gypsy,” “The Music Man” and “Bells Are Ringing.”
As the 1960s began, Ms. Kim struck out on her own. The costume budget for her first musical, Arnold Weinstein’s “Red Eye of Love” (1961), at the Living Theater, was roughly $250. She began her dance career the next year designing costumes for Glen Tetley’s “Birds of Sorrow,” a modern-dance version of a Japanese Noh play. Her first solo work on Broadway was for “Have I Got a Girl for You!” (1963), which closed on opening night.
In fact, her first four Broadway projects ran a total of only 12 days. But by the 1970s, her career was in full swing, bringing her Tony nominations for “Goodtime Charley” (1975), “Dancin’” (1978), “Song and Dance” (1985) and “Legs Diamond” (1988) in addition to her two Tony wins.
By the time Ms. Kim reached her 70s, people began to ask when she planned to give it all up. She didn’t. And in her 90s she admitted that while she did not consider herself retired, “everyone else seems to.” One of her last major projects was a new production of “The Sleeping Beauty” for American Ballet Theater in 2007.
She married William Pène du Bois, a cousin of Raoul, in 1955. William, a children’s book illustrator and author and a founder of The Paris Review, returned alone to Europe in 1972 but, according to Bobbi Owen’s book “Designs of Willa Kim” (2005), they remained in touch and he continued to attend many of her openings. Mr. Pène du Bois died in 1993.
Her survivors include her niece, Celeste Rosas. Her three brothers, Jack, Henry and Young O. Kim, a highly decorated World War II veteran, died before her.
Ms. Kim voiced only one regret. Given the chance to do it all over again, she said in 2009,“You know, I would be kinder.”