Living in Arizona we don't get many colorful leaves out here. Problem solved with this quick and easy project! (Most people have everything needed for this craft already at home.)
Tips: Cut various shapes and sizes of leaves to give them some variety. Use water based markers. Don't over spray the water because it could wash all the color out. It's okay if not every single spot on the filter is colored. After they are completed, make a tree with a crumbled brown paper bag for the trunk, hang them in a window to see the beautiful colors as the light shines through, or make a mobile or scatter them around the kids table at Thanksgiving. Have fun!