Place the flowers on a sheet of wax paper. Provide ample space between the flowers.
Spray the flowers with some water. Watch the colors spread and mix on the coffee filter. Let the flowers sit for a bit—it takes time for the colors to spread. If you want the colors to spread more, spray with a bit more water. Allow the flowers to dry completely on the wax paper.
After your colored coffee filter flower dries, you can do a few more steps to turn it from a flat two-dimensional flower to a three-dimensional one.
Pinch the center of the flower with one hand. Use your other hand to gather the petals towards the center as shown in the photo.