LONGPORT – Beachgoers here will be seeing purple when they go to the beach this summer. Along with the purchase of a beach tag, buyers will receive a clear rubber wristband that turns color in the sun. The purpose is to create awareness about the most common cancer among young people between the ages of 25 and 29 – melanoma. The bracelets, which will be available at Longport Borough Hall starting mid-April, carry the simple embossed message: “When Purple – Protect – Prevent Melanoma.” The bracelets contain a special powder that reacts to ultraviolet rays that causes the bracelet to turn purple when UV rays are detected, even on cloudy days.