We used two aspects of the Marketing Toolkit developed by the Washington State Conservation Commission and several members of our conservation community, plus an interesting article about painting with soil colors.
Painting with soil
An article in the Smithsonian Magazine about painting with soils illustrated a range of earth tones. We selected a brown color to reflect our interest in soil. Find that article at https://www.smithsonianmag.com/science-nature/meet-western-soil-scientists-using-dirt-make-stunning-paints-180976796/.