Combine sugar, butter and corn syrup in a heavy saucepan over medium heat. Bring to a boil, stirring constantly. Reduce heat to low and boil 5 minutes, stirring occasionally. Remove from heat and add vanilla; set aside. Combine powdered sugar, salt and powdered milk; stir into sugar mixture. Let stand about 20 minutes, or until cool enough to handle. Divide dough into 3 equal parts and place in bowls. Wearing plastic gloves, knead desired amount of yellow food coloring into one bowl of dough; knead desired amount of yellow and read into the second bowl to create orange. Leave remaining bowl uncolored. Roll each portion of dough into a long, thin rope of equal lengths. Arrange dough ropes side-by-side; press seams together using a rolling pin. Cut into triangles with a sharp knife; shape edges to resemble corn kernels. Set aside until firm; store in an airtight container.