the picture is of a green worm, but you can dye them any color you can find.
Step 1: Rainbow Worms
first you need a worm farm, and some "magic worm food," which you can find at Walmart for a couple bucks.
Step 2: Step 2
next you need food coloring, and a container to mix the food in. in the container mix 3 parts food powder and 1 part water stir until blended. add 3-6 food coloring drops into the worm food, mix until it is one color.
Step 3: Step 3
it might look gross but it should dye the worms any color you can find.
let me know how this works.