"Vermillion in the orange shadows, on a cold, fine day," Pierre Bonnard wrote in a sketchbook on one of his daily walks near his home, at Le Cannet, north of Cannes. Born in 1867 in a suburb of Paris, he settled in the South of France in 1926 with his reclusive wife, Marthe, remaining until his death in 1947. Such atmospheric observations infused the paintings that dominated the artist’s last three decades: window-framed landscapes and radiant domestic scenes depicting his wife going about her day. "The late interiors give you an understanding of how truly modernist he was," says Dita Amory, a curator with the Metropolitan Museum of Art in New York, who has organized the first exhibition devoted to these works, opening January 27. "Shadow is never gray or black. It’s violet or purple."

Bonnard made his mark early as part of the Nabis ("prophets" in Hebrew), the self-named group, including Maurice Denis, Édouard Vuillard and Paul Sérusier, that met at the Académie Julian, in Paris, in the late 1880s and experimented with suppressing perspective by using decorative pattern and flat areas of color. In the first decade of the 20th century, Bonnard struck out on his own. Dividing his time between the city and the country, he painted active street scenes in Paris and worked with professional models. By 1912 — when he bought a small house in Vernonnet, near Giverny, and his life with Marthe became more secluded — he had forged a distinctive technique, using oppositional hues that vibrated across his spatial fields.

"Bonnard is radically important to our understanding of the 20th century, and he’s one of only a handful of artists — including Picasso — who were able to almost reinvent themselves throughout their careers," says Guy Bennett, the head of Impressionist and modern art at Christie’s. "Undeservingly, he hasn’t been recognized in the market as someone of that importance, and I think the whole body of his work is undervalued."

The public’s perception of him is changing, however. To illustrate the shift, Bennett points to Bonnard’s auction record of $8.5 million, set at Christie’s New York in November 2006 — following a full-scale retrospective of his work staged the previous spring at the Musée d’Art Moderne in Paris — by his relatively small, 233/4-by-317/8-inch, late still life Deux corbeilles de fruits, 1935 (est. $5-7 million). "The painting captured those things that bridged the two ends of his career: the quality of flatness, or lack of perspective, and this great saturation of color. It’s exactly what the market was looking for," says Bennett. "If a significant late interior or nude were to come to auction, it would shatter the present world record."

Bonnard was a prolific artist and an indefatigable draftsman, producing gouaches, watercolors and pastels. He made close to 400 paintings of his wife alone, comprising large-scale nudes in which Marthe, shown in the midst of an obsessive bathing routine likely prescribed for her numerous ailments, is the focal point, as well as interiors featuring her, nearly camouflaged in brilliant light, at the periphery of a beautifully laid table.

The artist’s monumental canvases reside in both public and private hands and seldom surface on the market. The Phillips Collection, in Washington, D.C., for instance, owns 17 oil paintings by Bonnard, whose art the museum’s founder, Duncan Phillips, started collecting in depth in the 1920s. And some 50 works acquired by Bonnard’s friends Arthur and Hedy Hahnloser are in Switzerland with their descendants, who have lent one of their pieces to the Metropolitan show. Other lenders include the French collectors Sylvie Baltazart-Eon and Anisabelle Berès-Montanari and the American collectors Pilar and Stephen Robert and Henry Silverman.

The last time a really major example of a woman in an interior came on the block, according to Emmanuel Di-Donna, the vice chairman of Impressionist and modern at Sotheby’s, was more than two decades ago, in 1988, when the oil Après le repas, 1925 (est. $2.5-3.5 million), sold at Christie’s New York for $7.5 million — the artist’s auction record for the next 18 years. In 1989, at Christie’s London, Après le bain, a large undated watercolor and gouache nude, fetched £352,000 ($546,668), more than doubling its high estimate of £150,000 ($273,300). Twenty years later, the piece still holds Bonnard’s auction record for a work on paper.