It was amazing to find some people had never colored eggs. The process is fun and the materials are cheap. We boiled our eggs the day before, and we highly recommend the directions for hard-boiled eggs found on the egg carton. We used food coloring (10 drops), warm water (1/2 cup), and vinegar (1 tsp) to color the eggs. Masking materials we used included hot glue, white crayons, and rubber bands. Masking simply means that you are covering a portion of the egg in order to keep it white or some other color.
You can create designs with more than one color if you start with a light color like red or yellow (mask whatever portion you wish to keep that color) and move on to blue or green. If you want to make purple, you can dip your egg for a few minutes in red, and then a few more minutes in blue. The rules of color mixing are relevant when dying eggs, and if you start layering colors, it can look a little like batik. I was very pleased with the masking abilities of hot glue, but make sure your egg is dry, or the glue will not stick. I strongly recommend making egg stands out of cardboard tubes, they were very helpful. Have fun masking!