The book "Chesapeake & Ohio Passenger Cars in Color" by Harry Stegmaier, (TLC Publishing, Lynchburg, VA, 2001) has several interior shots.
Streamlined sleeping cars had light green wall with red upholstery. Curtains were a red and white print.
Streamlined dining cars, such as # 1920, appeared to have light green side walls, tan bulkhead walls, red leather seat upholstery, black, white, brown & gray diamond print curtains and black or dark blue floors. Couldn't tell if they were carpeted or linoleum.
Coaches had red linoeum floors with white four-pointed stars and white stripes running next to the seats, which had olive green upholstery. The walls were tan and green. The cars also had the same curtains as the dining cars.