Place ~4-6 same-color Jolly Rancher candies into a jar or container with a lid. Pour 4 ounches of vodka over the Jolly Ranchers and cover the container with an airtight lid. Allow candies to dissolve in the alcohol for about 24 hours. Stir or swirl occasionally to help combine the mixture.
When ready to make the cocktails, fill glasses with ice. Add two ounces of candy alcohol to each glass.
Fill the glass the rest of the way with lemon-lime soda.
Top with Jolly Rancher candies and serve.