From Iowa to Studio 54, this investigation into the rags-to-riches story of America’s first superstar designer uncovers the cautionary tale of an artist who sold his name to Wall Street.

IRIS pairs legendary 87-year-old documentarian Albert Maysles with Iris Apfel, the quick-witted, flamboyantly dressed 93-year-old style maven who has had an outsized presence on the New York fashion scene for…