After eggs have been boiled & yolks removed, fill glass containers about half-full of water & add food coloring. Place egg halves in water, making sure the entire surface is covered. Let sit at least one hour, place them onto wire rack to dry.
Cook spaghetti noodles, drain and cool. Fill a gallon Ziplock bag with water. Add food coloring to the water. Add part of cooked spaghetti and mix around in the ziplock bag until noodles change color. Drain, repeat with other colors.