Line a baking sheet with parchment paper. Set aside until later.

Sift 1 cup powdered sugar into a large bowl. Add corn syrup, vanilla extract and 1½ Tablespoons water to the powdered sugar. Beat well until smooth and lump-free. Sift and add the remaining ½ cup powdered sugar. Mix well until fully combined, flowing and "pipeable". TIP: If necessary, add a bit more water (about 1 teaspoon at a time) until mixture is smooth, thick yet flowing enough to be easily piped through a pastry bag tip.

Divide icing into small bowls based on the number of colors you're making. Add food coloring as needed to achieve the color you want. Stir food coloring into the icing to distribute color evenly. TIP: Colored icing will lighten and fade slightly as it dries and hardens overnight, so add just a tiny bit more food coloring than you think you should.

Load pastry bags with various colors of icing. If using a pastry bag, fit it with a size 3, 4 or 5 tip. **If using Ziploc-style bags, spoon each color of icing into the bottom corner of individual bags, release the air, then seal the bags. Squeeze the icing down into one corner of the bag, twisting the top of the bag down tightly on the icing. Use scissors to cut across the bottom corner of the bag. This opening should only be big enough to pipe a thin line of icing through.

Pipe thin lines of colored icing onto the parchment paper-lined baking sheet, squeezing icing out of the bag as you go. Try and get the lines as straight as possible and make sure they don't touch each other. HELPFUL TIP: When piping the lines, try to keep the pastry tip (or corner of the bag) about ½" above the parchment paper. Squeeze the piping bag and pull the lines forward as you pipe the icing. Set the baking sheet full of "future" homemade decorative sprinkles aside. Let them dry (and harden) COMPLETELY overnight (about 12 hours).

After they have dried completely (12 hours), use a knife to cut each colored line of icing into ¼"-½" long pieces. When done with each color, set them aside. Repeat until all colored lines have been cut into desired sizes. Store sprinkles in airtight containers for up to a year.