Step 1Using a spoon, scoop out the fruit of the oranges, leaving the peel intact. Place empty orange peels on a muffin tin to stop them from falling over. In a medium bowl, combine one box Jell-o mix with 1 cup boiling water and whisk to combine. When the mix is dissolved, stir in 1/2 cup cold water. Transfer to a liquid measuring cup and fill half of the oranges. Repeat process with remaining ingredients. Refrigerate until the Jell-o is firm, about 4 hours. Meanwhile, make toothpick sails. From the colorful paper, cut out small triangles and rectangles as sails and skewer them onto toothpicks, using 1 triangle and 1 rectangle per sail. (Depending how thick your paper is, you may want to pierce holes with a needle first to prevent the paper from tearing. ) Slice each orange into wedges, then stick a toothpick sail into the Jell-o. Serve immediately.