Let the rubber cement sit for a bit, but not for too long. Around 5 minutes or until it starts to feel or look more gooey. Then after that, bust out your colored pencils from an art kit, or just colored pencils. Take the pencils and run them through a manual pencil sharpener at an angle, so the shavings coming out of it are only colored pencil, no wood. What this does is create a really low grade makeup. The colors you will need is a deep red, black, a light purple, and a dark purple. To start, use a paintbrush(dry) and dab it into the black makeup and apply it near the center of the scar, then overlay some red onto that. After that, apply the darker purple on the inside, and the lighter purple on the outside of the scar.