What You’ll Need
Hard-boiled eggs, room temperature (white or brown eggs, preferably not super-fresh)
1 cup chopped purple cabbage per cup of water
1 cup red onion skins per cup of water
1 cup yellow onion skins per cup of water
1 cup shredded beets per cup of water
2 tablespoons ground turmeric per cup of water
1 bag Red Zinger tea per cup of water
White distilled vinegar (1 tablespoon per cup of strained dye)
Liquid neutral oil, such as vegetable or grapeseed
Saucepan with lid
A second saucepan or bowl
Baking dish or other container
Gather your ingredients: You can make separate batches of different colors or one large batch of a single color. Follow the ratios given above for each ingredient to make more or less dye.
Add water to a saucepan: Pour the amount of water you need for the dye you’re making into a saucepan.
Start making the dye: Add the dye matter (purple cabbage, onion skins, etc.) and bring the water to a boil.
Adjust the heat: Turn the heat down to low and simmer, covered, for 15 to 30 minutes.
Check the color: The dye is ready when it reaches a hue a few shades darker than you want for your egg. Drip a little dye onto a white dish to check the color. When the dye is as dark as you like, remove the pan from the heat and let the dye cool to room temperature. (I put the pot on my fire escape and it cooled off in about 20 minutes.)
Strain the dye: Pour the cooled dye through a fine-mesh strainer into another saucepan (or into a bowl then back into the original pan if that’s all you have).
Add vinegar: Stir the vinegar into the dye — use 1 tablespoon of vinegar per cup of strained liquid.
Pour the dye over the eggs: Arrange the room-temperature eggs in single layer in a baking dish or other container and carefully pour the cooled dye over them. Make sure the eggs are completely submerged.
Put the eggs in the fridge: Transfer the eggs in the dye to the refrigerator and chill until the desired color is reached.
Dry and oil the eggs: Carefully dry the eggs, and then massage in a little oil to each one. Polish with a paper towel. Store the eggs in the refrigerator until it is time to eat (or hide) them.
You can also start with raw eggs and cook them in the dye bath as described in this post on onion-skin eggs. I found that with dyes like the Zinger tea and beets, the color was more concentrated with the refrigerator method. Of course, this method requires clearing out some space in the refrigerator.
If you want your eggs to be more vibrant and less pastel, give the eggs multiple soaks in the dye, being sure to dry them between stints in the dye.