Each year before Easter, I buy the egg dye kits, lots of eggs and let my girls have fun dying eggs. It's not a particularly messy project, and very simple to accomplish. The results are just beautiful. The picture at top is the Paas eggs. Good ol' Paas. The package hasn't changed in 40 years. I've used the coloring cups in the past, but they are more expensive and dye fewer eggs, so this year I used the traditional package.
The eggs at the bottom are from a kit called Dudley Majestic eggs and involved kneading a package of dye and then coating individual eggs in a plastic bag. The eggs are spectacular - very unusual.
A couple of notes: I can't imagine eating colored eggs, so I just leave them at room temperature and enjoy them as decorations on the table. They can be used in an egg hunt, but we also put out candy-stuffed plastic eggs so the kids get something better than a (very pretty) rotten egg. And when shopping for eggs, look for the medium size - they are usually the best deal when you buy in quantity.
I wish the blessings of Easter and Passover to my friends and family this year.