The book Pensy Streamliners by Joe Welsh has some color interior photos of the recreation car and diner. The recreation car has off white walls. dark green floor, and light green seating. The diner has a maroon floor, off white walls, tables with white table clothes, maroon dinning chairs, maroon curtains. There is a service area in the diner's center painted green with a stainless steel top.
Another Joe Welsh book, Pennsylvania Railroad's Broadway Limited, has color illustrations and photos. The diner is the same as above. The sleeping car illustration has a dark floor (almost black - maybe dark blue or maroon), light blue walls, and maroon seats. The observation car has a dark blue floor, off white walls, and a mix of blue and maroon furniture. I recommend this book if you want to see a variety of interiors. It was published by MBI in 2006.
NH Joe