The back sides of the pipes, which had not been visible until they were cut down, showed the vestiges of several different layers of paint. Much to my satisfaction, the order of these colors matched those that I had found in several other places throughout the house.
Soooo, I am now fairly certain that we know the original wall color of the house, as it looked in 1897...This mauve-ish color looks to be the original paint. This color, together with all the natural woodwork (before it was painted many, many times) must've looked really beautiful.
I am a regular Nancy Drew.