There are a few ways to do a gender reveal with Tannerite and chalk. One way is to put the Tannerite in a container with pink or blue chalk. When the Tannerite goes off, it will reveal the color of the chalk, indicating the baby's gender. Another way is to put the Tannerite in a container with pink or blue powder. When the Tannerite goes off, it will reveal the color of the powder, indicating the baby's gender.