MAKE THE EGGS: Bring 6 cups of water to a boil and add the tapioca pearls. Reduce the heat slightly and boil the pearls, stirring occasionally, for 20 to 25 minutes.
COLOR THE EGGS: Divide the pearls, with the remaining water, between two bowls. Add 4 drops of food coloring (we used 3 drops of yellow and 1 drop of green in one bowl, and 4 drops of blue in the other) and 2 tablespoons of sugar to each bowl. Stir the mixtures, then allow them to sit uncovered for 20 to 25 minutes. Drain and rinse the pearls with cold water.
ASSEMBLE THE DRINK: Spoon 2 tablespoons of pearls into each glass and drop in a gummy fish. Fill the glasses with seltzer water, then add a splash of lemonade. Place a gummy worm around a spoon as shown.