Paint samples from the Front Parlor identified blue paint at layers six and seven in the paint stratigraphy. These two layers were preceded by several layers of cream colored, oil paint and followed by a layer of pinkish cream paint.
An 1877 magazine article noted that the room was painted blue at that time. The documentary records of the 1879 room restoration also confirmed that the paint applied at that time was changed to a light color.
Therefore, the combination of paint analysis and research allowed for the dating of layer seven (blue) as circa 1877 and layer eight (pinkish cream) as 1879. By extension, layer six (light blue-gray) could not have dated to the 18th century as it would have had to be on the walls for multiple decades, but there was not a significant accumulation of dirt on top of it.
Further, the first layer could be dated alongside the installation of the wood paneling between 1758 and the early-1760s. After that initial painting, there was documentary evidence for three more paint campaigns before Washington died in 1799.
Thus, by both backing into and building up to the stratigraphy sequence, one of the early cream layers could be firmly identified as the 1790s paint color (as was suspected in the 1930s sampling).