1. Prep Your Eggs
Place your eggs into a shallow container of vinegar to prepare them to take the dye. This will create the most vibrant colors. Keep the eggs in the vinegar for at least 20 minutes, but keep in mind that the longer the eggs steep, the more brittle the shell will become. Don't leave them any longer than four hours or so.
Carefully rinse the vinegar off of the eggs and pat dry before continuing.
2. Set up the Shaving Cream
In a muffin tin, fill each cavity approximately 2/3 full with shaving cream. If your pint-sized helpers add more, don't worry: It won't affect the results of the craft, it will just make things a bit messier.
Be sure to use shaving cream—not gel. No need to use the expensive stuff: We purchased the cheapest available from our local grocery store with great results.
3. Add the Color
Add a healthy drop of gel food coloring in two or three complementary colors on top of the shaving cream in each cavity. Take care when making color selections—orange and blue are pretty together, but when mixed, they make brown.
This is a messy craft. Be sure to protect your work surface and wear gloves if you'd prefer not to have colorful hands for the next couple of days.
Use a toothpick or a wooden skewer to gently stir the food coloring into the cream, adding another drop of color if needed.
A gentle swirl of your skewer will give you a marbled effect on your finished eggs, and a more vigorously combined mixture will give you more color on the eggs with less white areas and less definition between colors.
Both techniques make pretty eggs, so feel free to experiment to find the results you're happiest with.

You can use liquid food coloring instead of gel if it's what you already have on hand, but your results will be a little different from ours. The thinner dye will spread considerably more in your shaving cream, giving you less definition in the colors, and won't produce as much of a marbled look.
4. Create Your Designs
Gently place your dry egg on top of the colored shaving cream in your muffin tin, trying not to allow the egg to touch the bottom of the tin.
Carefully fold over the shaving cream on top of the egg to completely cover it.
Continue for all of your eggs and give the tin a few gentle taps to allow the shaving cream to settle into any air pockets.
Allow the eggs to sit in the mixture 10 minutes for more pastel colors and overnight for bolder colors. We wanted a look somewhere in the middle and allowed our eggs to sit for about half an hour.
5. Remove the Shaving Cream
Once the color has set, rinse your eggs directly under the tap, using your hands to help remove the cream. Gently pat your eggs dry with a paper towel and place on a smooth surface to prevent the transfer of a pattern or texture. A cookie sheet lined with parchment paper works very well.