Step 1

Combine sugar, 2 tablespoons water, corn syrup, and vanilla in a small bowl. Stir until mixture has consistency of glue, adding more water if necessary, 1/4 teaspoon at a time. Divide into 3 small bowls; tint with food coloring as desired.

Step 2

Transfer lightest-colored mixture to a pastry bag fitted with a small pastry tip (such as Ateco #2). Pipe long, thin lines onto parchment-lined baking sheets. Fill pastry bag with medium-colored mixture; repeat piping. Fill pastry bag with darkest-colored mixture; repeat piping. Let stand, uncovered, until very firm, at least overnight. Once lines are dry, break enough into small pieces for 1/3 cup; keep remaining sprinkles long for garnish.