Iris Apfel isn’t exactly a household name, unless we’re talking about very stylish households. From 1950 to 1992 Apfel ran Old World Weavers, the business she co-founded with her husband, Carl, which faithfully re-created antique textiles for use in home decorating: From grand Park Avenue drapes to demure White House settees, the duo’s historically accurate fabrics made their way into any number of upper-crusty redecorating schemes. But today Apfel, 93, is less well known for dressing interiors and more famous for dressing herself. She’s what’s known in fashion parlance as a style icon, though the fatuous blandness of that term doesn’t come close to describing the visual exuberance of her look: On a random day Apfel might sport — in addition to her trademark cropped silver hair and round-rimmed spectacles — a satin patchwork jacket in Marrakesh colors, a pair of velvet smoking slippers with a screw embroidered on the toe of one and the letter “U” emblazoned on the other, and no fewer than six jumbo amber bead necklaces. Plus five bright Bakelite bangles — on each arm.

Apfel is the subject of Albert Maysles’s Iris, one of the final documentaries made by the revered nonfiction filmmaker before he died this past March. And like all good documentaries, Iris is about much more than what we see on the surface, no matter how dazzling that surface may be. Apfel and her colossal feats of accessorizing have been featured in countless magazine spreads, and museum shows have been assembled from her decade-spanning collection of clothes and accessories. She also sells a line of costume jewelry on the Home Shopping Network. Apfel sometimes packs more into a day than younger, sturdier souls might attempt in a week, and people who care about fashion adore her at least partly for her classic New York candor. (In Iris, more than once someone will ask her solicitously, “How are you?” to which she responds, “I’m vertical.”) Maysles’s camera captures the self-described “geriatric starlet” hobnobbing with Linda Fargo, a senior vice president at Bergdorf Goodman and the doyenne of the store’s famous, fabulous windows, and greeting the elfin New York Times street-style photographer extraordinaire Bill Cunningham with a genuinely affectionate (as opposed to a fashion-world) embrace.

But Iris is more than just a movie about an amusing lady who likes clothes an awful lot. It's also a celebration of the revivifying power of creativity, whether we’re painting a companion piece to the Sistine Chapel ceiling or deciding what color pocket square to wear in the morning. On camera, Apfel laments the “homogenization” of modern dressing: “I like individuality. It’s so lost these days.” She tries to explain how she puts things together the way she does, by gathering bits and bobs from flea markets, from junk-jewelry stores in midtown Manhattan, from her world travels with Carl. “I like to improvise,” she says. “It’s like playing jazz.” The truth is that once in a while Apfel will start with a garment that’s at least mildly atrocious — a jacket, say, with too-garish embroidery. But by the time she’s done putting a look together, it’s all like a peculiar piece of music, maybe not hummable but defiantly distinctive — the visual equivalent of Mingus’s rubbery, jolly bass solo on “All the Things You Are.”

Maysles’s camera opens its eyes wide to Apfel, taking the measure of her wildly beautiful and witty outfits as if it can hardly believe what it sees. There’s delight here in Maysles’s way of seeing. When it’s time to go, this is the way to do it, with nothing but openness to joy and beauty: Iris is a wonderful parting shot. It’s also very quietly moving, considering that it’s not about growing old, but about already being there. As the film was being made, Iris, Carl and Albert were already members of this club — Albert, at 88, would have been the youngest — and even if their curiosity about the world hasn’t diminished, they’re hardly in denial about the creakiness of their bones. Apfel has plenty of salty words about the inevitability of wrinkles and the necessity of just getting up and moving, even when every body part aches. Carl is less vociferous about the inconveniences of aging, but Maysles’s camera captures, with the delicate touch of a watercolor brush, the fragility of his health: We see him celebrating his 100th birthday, quietly seated in a wheelchair but still radiating boyish delight — not least because he clearly gets a kick out of just about everything his wife says, does, or wears, even if he occasionally feigns a weary shrug.

The picture’s loveliest, most offhanded moment involves a rather protracted discussion between Iris and Carl about whether or not there’s any yogurt left in the refrigerator and, if so, whether it’s “his” or “hers.” This is what life comes down to when you’re 93 and 100, respectively. But beyond that, the exchange is just one little thread plucked from the intricate warp and weft of married life, the wild, imperfect tapestry you make together when you’re with someone — devotedly, as these two are — for a long time. At one point Apfel states simply that she likes being “in the world and of the world.” She may wear six necklaces at once, but she knows how to pare down to the basics.