Barnett Newman, a seminal figure in the Abstract Expressionist movement, is known to have used Bocour Magna, Aqua-tec, and oil paints. XRF analysis reveals that paints on his paintings dating from 1967 to 1970 and on his undated ephemera in the Center for the Technical Study of Modern Art at Harvard Museum and the Menil Collection most often do not correspond to the pure historic Bocour paints available for analysis. Newman likely mixed his paints to create specific colors, and multiple instances of his revision of color have been documented. Some of the paints on the paintings are similar to unlabeled jars of red and blue acrylic paints found in his studio after his death, which could contain bespoke formulations created for Newman by the Bocour Company. The white paints and grounds present on the paintings and ephemera are all titanium white based; early works have no calcium, but later works have increasing amounts, suggesting that Newman may have been adding more calcium carbonate as an extender over time. The similarities in white paints on groups of paintings and ephemera suggests Newman used a given paint mixture on multiple objects, which would allow temporal relationships between those objects to be established.