The colour in the title of a new exhibition in London, Whistler’s Woman in White, refers to the dress in which James McNeill Whistler famously painted his favourite model, subject of the show.
But the most visually striking thing about Limerick-born Joanna Hiffernan, however she dressed, was her glorious hair, variously described as red, copper-coloured, or "flaming".
It also captivated at least one other major artist, Frenchman Gustave Courbet, earning her the name by which he too painted her in a series of portraits: "La Belle Irlandaise".
The sensuality with which Whistler depicted her was almost shocking for its era: the 1860s. Her full-length, flowing white dress did little to diminish this.
On the contrary, that may have been an artist’s joke. There was nothing virginal about their relationship. They were lovers at the time.
As painted by Courbet, Hiffernan was also on occasion the woman in nothing. His 1866 work, Le Sommeil, features her as one of two nude females, sleeping but entangled on a bed.
And for many years she was also the suspected model for an even more risqué picture, L’Origine du Monde.
That too depicts a reclining nude, but only from the waist down.
A strong argument against Hiffernan’s involvement is that the model’s coiffure is not red. Then again, Courbet could have had reasons to disguise her, not least that she was still Whistler’s partner then.
In 2013, a Courbet expert authenticated a matching top half of the painting, which might have settled the argument. But the Musée d’Orsay, where L’Origine du Monde resides, insists it was never part of a larger work.
And the most recent breakthrough by art detectives was the 2018 discovery of a reference to the picture in 19th-century correspondence between Alexandre Dumas fils and George Sand.
If that is correct, the model was a dancer in the Paris opera, Constance Quéniaux, and the Woman in White’s modesty has been belatedly preserved.
Not much is known about Hiffernan’s early life except that she was born during the Famine, in 1843, and moved to London soon afterwards. Her father was a teacher of calligraphy at one time, but was also likened by friends of Whistler to the “Captain Costigan” of a WM Thackeray novel.
A better class of stage Irishman, Costigan was a hard-drinking career soldier who claimed to be a descendant of kings and to have a castle back in the old country, albeit in distressed state.
His creator claimed that, having already sketched out the character mentally, he met the real thing one night in a pub: “The same little coat, the same battered hat, cocked on one eye, the same twinkle in that eye . . . Of course he had been the in army.” When Thackeray offered to buy him a brandy, the man answered “Bedad you may”, and offered to sing a song in return.
As the fictional Costigan might have done, Hiffernan’s actual father took to referring to Whistler as “me son-in-law”. But although the relationship lasted years, and Whistler was said to enjoy his muse’s wit and intelligence as much as her beauty, they never married.
In her own way, like her father, Hifferan may have been playing an established role abroad. She was not the first artist's model in France to be called La Belle Irlandaise.
A century earlier, the same title had fallen on Marie Louise O’Murphy (1737-1814), born in Rouen of Irish heritage, who rose to be mistress of Louis XV, a job that came with a cottage in Versailles.
She also earned permanent residence in the Louvre and elsewhere, courtesy of nude portraits by Francois Boucher, who called her "O-Morphi", a pun on the Greek for "beautiful".
But the combination of Irish women and French background lighting seems to have been generally irresistible. In a 1768 letter, even Scottish writer James Boswell, back from the continent, declared himself in love with a teenage "Belle Irlandaise", who was "formed like a Grecian nymph, with the sweetest countenance, full of sensibility [and] a Dublin education".
Little is known of Joanna Hiffernan’s later years, although even after parting from Whistler she helped raise a son he had fathered elsewhere. She was said to be living in Nice in 1882, selling antiques and Courbet paintings.
But in a late recorded sighting, from 1903, she was the woman in black, or one of them.
It was Whistler's funeral, where art collector Charles Freer watched as a mystery mourner raised her veil to reveal "the thick wavy hear [that although] streaked with grey," he recognised immediately from the paintings.
Freer was also impressed by the depth of her feelings for the departed. She stood by the coffin, he recalled, “for nearly an hour”.