Put on rubber gloves, and mix up your fabric dye according to the package directions. Fill plastic squeeze bottles with each color that you want to use. After attaching the lids to the bottles, shake well in to mix the dye.
Cover the work surface with plastic. Soak the pair of shorts in cold water, remove them from the water and wring them out. Tightly bunch up sections of the shorts to create your preferred pattern. Secure each section with a rubber band. Lay the shorts on the plastic-covered work surface.
Apply your desired color of dye to each bunched-up section of the shorts. Continue applying color until all areas are covered. Let the dye set for about three hours. After the shorts have dried, rinse each section under cold water until the water is running clearly. Use scissors to cut off the rubber bands and lay the shorts flat to dry.