In My Way of Life (1971) Joan writes:

...My next move was from the big Fifth Avenue duplex to the much smaller apartment I live in now....I had only a few blocks to go. But I had to dispose of a great many things and again it was a question of deciding what to send to Parke-Bernet for auctioning because I have much less storage space here for china and crystal....

I have the lovely upholstered pieces that were made for the Fifth Avenue apartment, and some of the fine Chinese pieces I acquired in California. My living- and dining-room walls, and those in the hall, are white. The sofas are egg-yolk yellow--not a metallic gold shade, which I find harsh. The linen draperies, too, which I brought from the other apartment and had shortened, are egg-yolk yellow with white linen behind them. (When they're washed only one set is taken down at a time, so that there's always something at the windows.)

The yellow is a lovely soft background for the leaf-green accents on small chairs and stools. The sofas are banked with green and yellow pillows, sparked with two chintz pillows in green and white. The same colors flow into the dining room, which seats eight very comfortably and ten if necessary, at a yellow baked-enamel Parsons table that I have covered with yellow felt for everyday wear and tear.  The dining-room curtains have a pale-green-and-white floral design. The chairs are covered in green leather.

The living room is L-shaped, giving the effect of two rooms, and in each I have a large green area rug bordered in yellow. Lamps, sculptures, and bibelots, some I've had for decades, stand out strikingly against the white walls. And there are masses of green plants and flowers at all times of the year. There's a long low breakfront displaying the miniatures I've always loved collecting, and the hall is lined, floor to ceiling, with bookshelves containing books I've managed to keep with me from other years, and the new ones that seem to come in every day.

I've said that I avoid chintz, but very bravely I've added an armchair done in the same pattern as the pillows and the dining-room curtains and it's a great improvement. It softens and warms the room....

I'm beginning to run out of wall space. I have Margaret Keane's paintings, which I love, hanging in my bedroom and dressing room, and I think I would start putting them in the bathrooms if the walls weren't tiled to the ceilings.

In his 1980 book There's No Place Like Home, designer Carleton Varney writes of Imperial House 22-G:

Joan and I planned her new nine-room apartment down to the last shelf. Custom-made cabinets were designed to house all her china, silver, and glassware. We turned the former maid's room into a hat and shoe room. A second bedroom became Joan's dressing room and was outfitted with wall-to-wall closets. A third bedroom was for Mamacita. We planned to decorate the apartment in -- you guessed it -- lemon yellow, white, and beige. I was to use many of the Billy Haines pieces, but I did manage to convince her to stain the blond tables a rich ebony. Because there was no room for her long dining table, we made a new lemon yellow lacquer piece. Joan instantly covered it with a top of yellow felt to protect it from becoming scratched. "People are so careless with ballpoint pens," she explained.

All the windowsills in the apartment were covered with white plastic laminate so that they could be cleaned without damaging the paint... Joan's new dining room carried out the scheme of something old, something new. In the white-painted room I used green and white palmlike patterned drapes at the windows. Black framed chair seats were covered alternatively in lime green and lemon yellow washable vinyl. The room was good-looking in spite of the plastic, but it was rarely used for a sit-down dinner....

Her apartment revealed mementoes from three friends... One was a picture of Noel Coward, who never came to town without seeing her. Another picture was of Barbara Stanwyck, whom Joan called Missie, and on her night table sat a pair of porcelain hands that Helen Hayes had given her....

There was lots of sunshine and a feeling of space; particularly pleasant was the big sunroom with the two terraces on either side. We had also made a few architectural changes, opening walls to let in more light, and removing all the bathtubs and putting in stall showers instead. "I don't like to sit and soak in my own dirt," said fastidious Joan. I also convinced Joan to get rid of the white rugs and live a little, and we laid custom-made green rugs with yellow borders.