During the 21st century mansion restoration campaign, paint testing revealed that the window sash, baseboards, door casing, and shelves located in the small closet in Nelly’s Best Room were painted Prussian blue around the time of their construction in the 1760s. Invented early in the 18th century, Prussian blue paint has been found in similar Virginia homes of the period. When walls in other public areas of Montpelier were repainted or papered during the 19th century, this space remained unchanged, likely because a door was installed and it was deemed unnecessary to update a storage space. The window, which features ca. 1760s glass panes, is the only surviving fenestration from the original Madison Sr. home.