In a large bowl, whisk together pudding mix and milk, about 2 minutes.
Divide the pudding evenly between 6 smaller bowls or containers.
Add 2 drops of each different color into different containers, and stir to color the pudding mix.
To add the pudding to your popsicle molds, pour each color into a separate frosting piping bag. This is the easiest way to get the colors in without them smearing the sides of the molds and blurring the colors too much.
Snip off the tip and divide the pudding between the 8 molds, starting with red first, then orange, yellow, green, blue, and purple.
Each popsicle will need about 4-5 teaspoons of each color for each layer, you will most likely have just a bit of extra left of each color that you can discard, don’t feel like you have to use up all of each color.
Once you have all of the layers done, add your popsicle sticks to your molds and freeze the popsicles overnight.