Cover a baking sheet with a piece of parchment paper.
Pour uncooked pasta into a plastic Ziploc bag. Add 1 teaspoon white vinegar and a few drops of food coloring.
Seal bag and shake vigorously until pasta is evenly colored. [the more food coloring you add, the brighter the color].
Pour pasta onto parchment paper to dry for about 10-15 minutes. Repeat as desired with different colors and new bags.
Video
Notes
Protect your space- We recommend lining your surface with parchment paper and having wet paper towels handy for spills and messes.
Don't overdo it with the liquid- Only mix 1 t of vinegar with a couple drops of food coloring. Too much liquid will pool inside the pasta and instead of drying, the pasta will be sitting in liquid.
Use enough pasta- Make sure there is enough pasta in each bag of coloring/vinegar. If the amount of pasta is too small, the pasta will be swimming in liquid.
Spread out pasta as it dries- Spread the pasta as widely as you can on parchment paper so the individual pieces will dry. And keep the colors separate.
Keep in mind that it may be hard to fully color pasta with folds and crevices (like bow tie pasta). These noodles may need slightly more food coloring.