[3] The interiors, which exist largely unchanged, were created by Elsie de Wolfe – later to become Lady Mendl – a former actress who had recently opened an interior-design business, and whose companion, the theatrical agent Elisabeth Marbury, was one of the club's founders.

Stanford White was slain by Harry K. Thaw months before construction of the Colony Club was completed.

The building was designed in the Federal Revival style, and has unusual brickwork done in a diaper pattern[3] as a notable feature of its facade.

[2][6] According to Andrew Dolkart: This is not one of Delano & Aldrich's more elegant works in the Colonial idiom, perhaps because it was nearly impossible to create a well-proportioned design for a building with the complex spatial requirements of this club.

The beautifully appointed interior included the lounges, dining rooms, and bedrooms common to social clubs, but also had a two-story ballroom, a basement swimming pool and spa that connected via an express elevator to a gymnasium on the fifth floor, two squash courts, servants' rooms (in 1925 there were thirteen female servants), and even a kennel where members could leave their pets.