If you’re choosing trash cans for a historic downtown, I’d start with muted forest green or deep olive. Those colors feel familiar next to brick, limestone, cast iron, and old streetlamps, and they hide everyday dirt well. Charcoal or dark bronze is a close second, especially if the district already has black lampposts and dark awnings. Dark brown can work near red-brick buildings, but it can disappear too much.
I’d avoid bright blue, safety yellow, pure white, and shiny aluminum, because they pull attention away from the architecture. The finish matters as much as the color: choose a matte powder-coated surface, a simple shape, and metal details that echo nearby benches or railings. If the downtown has a historic color palette, sample a color from it and repeat that same can color along the main blocks. You want the can to be easy to find but not memorable. In most historic downtowns, that means a quiet deep green first, charcoal second, and dark bronze third.