Bistre (#3D2B1F) and Heliotrope gray (#AA98A9) appear together across 6 master palettes in our corpus, most prominently in the work of Tobias Stranover, Thomas Cole, and George Stubbs and the Romanticism tradition. Painters typically deployed bistre at an average of 20% of the canvas, with heliotrope gray at 8%. Third colors most often completing the combination include Smoky black (#100C08), Van Dyke brown (#664228), and Lavender gray (#C4C3D0).