Pour the pasta into sandwich bags. Use any type of tubular pasta that you can string, such as penne or rigatoni. You need to use a different bag for each color of pasta you want to make. The amount of pasta for each bag depends on how many necklaces you're making and how many different colors you want to incorporate into the necklace. As a rough estimate, fill each bag approximately 1/4 full with pasta.
Add 3 to 4 drops of food coloring and one tablespoon of rubbing alcohol to each baggie. Shake vigorously to allow the mixture to coat each piece of macaroni.
Pour the pasta onto paper towels to allow it to dry. Do not work with it until each piece is completely dry to avoid staining fingers, surfaces and clothing. Place it in the sunlight to speed up the drying time.
Cut a piece of yarn long enough to fit over your child's head, leaving some extra room for comfort. Tie a large knot at one end to prevent the pasta from slipping off the end.
String each piece of macaroni on the necklace. Let your child be creative and string them on in any order desired. They can alternate colors or types of pasta or create patterns to make their creation their own.
Tie the two ends together securely once the macaroni is on the necklace.