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. :)
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.
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.
Second, more colorful batch
Have a messy, fun time. :)