Why use artificial colors to dye Easter eggs when you can use natural items you already own?
There is no real recipe. Just boil the vegetables, etc. and then simmer for about 15 minutes until a rich, dark color is achieved. The color of the egg will be lighter than the liquid but if you leave the eggs in the liquid for hours, they will become quite vibrant.
To change it up a little, try dipping them in little stockings made from onion bags, wrap rubber bands around them, or use old birthday candles to create waxed designs.