The second and third floor hallways are painted to look like granite, even to the extent that mortar lines have been added. This was very common paint detailing in the 1880s. Notice that there are three different shades of blocks incorporated into the wall.
Be sure to look up and see the original skylights. During the 1940s the skylights and the light wells were covered. Floors were constructed across them and they had been used as storage. Part of the restoration was to open them up and allow the natural light to filter into the interior spaces. A portion of the original terrazzo floor was left under the north skylight so it can be seen today.