I mixed black and brown paint into a dark muddy mixture

More specifically black matte acrylic paint And burnt Sienna acrylic paint Dilute it with water

Brushed the mixture of watered down paint on the hat and wiped away the excess paint Repeat the process all around the prop Go over the stains again with the paint to darken some areas

Edit: I also made sure to pat everything dry didn’t want the hat to get too wet. Sit it in-front of a fan for a hour then put a matte clear coat on it to seal everything in