A few days ago we did a project involving coffee filters. Instead of coloring them with markers and spraying with water, we used droppers and colored water. To make a sunset sky, we used red and yellow water. The kids picked up some water in the dropper and slowly squirted it onto their coffee filter.
Side note: I think I must have put in a lot more food coloring last year and that's why the Wild West one is so bright. So I guess if you want it extra bright, use lots and lots of food coloring!