Let's see if I can do a "how to" with the help of some photos and my kids.
First off, boil some eggs. We put eggs in cold water and then bring them to a boil, remove from heat, and let the eggs sit covered for approximately fifteen minutes. Now, you can boil the eggs for five minutes to make sure that they are cooked. We didn't cook them long enough once and the results were not pretty. Think runny goo. :)
Next, prepare your tray, or in our case bowls (we did the tray first and the kids didn't like the colors, so we switched to bowls). Preparing the tray/bowls is pretty easy, you take shaving cream (Barbasol is pretty cheap, so we used that), shake the can and spray the cream into each bowl or tray.
Next, add your food coloring. My kids wanted some with just one color and some with multiple colors, so we had a lot of bowls out (picky kids).
You then stir the food coloring, with either a toothpick or a spoon. One batch we mixed it up too much (I think) and we ended up with green goo, and the colors didn't seem to be as vibrant. They still had color though, but they were more of a pastel.
After stirring in your food coloring comes the fun part.
I don't have a picture of the actual rolling, but the result looks like this.
And the kids look like this.
And this.
You might want to use gloves, but the kids didn't seem to mind.
After your eggs are smothered in a colorful mess, you let the eggs sit and dry - this will help the colors adhere to the egg. We let them sit for seven minutes.
Now I have read elsewhere that you wipe the eggs off with some paper towels, but that seemed wasteful and messy to me, so we just rinsed them off with water. I don't think it made a difference, so you do it whichever way you desire.
First batch
Second, more colorful batch
Have a messy, fun time. :)