Yesterday I had a lot of fun making making these:
You will need:
Rubbing Alcohol (Isopropyl)
Pasta (doesn't matter what shape)
Place a couple Tablespoons or so of rubbing alcohol into a ziploc and add plenty of food coloring (I think I ended up adding like 15-20 for the red and purple, less for the blue and green). Mix and then add pasta. Close bag and then mix with your fingers to evenly dye/coat all of the pasta pieces. If the colors are not as bright as you want, add more food coloring. Let them sit for an hour or so, mixing them up periodically to really let the colors penetrate.
Pour onto paper towel lined baking pans, spread into a single layer (use a fork so you don't dye your hands) and let dry several hours to overnight.