What a fun idea for kids - make this year's batch of Easter eggs with natural dyes! Have the kids think about it, and decide which foods might be useful to dye eggs. Have you ever eaten fresh berries and stained your hands? Maybe the dye from the berries would stain eggs too! Some other popular choices are grape juice, spinach, beets and onions.
The first step, of course, is to hard boil your eggs and let them cool and dry. Vinegar is a natural preservative, and also helps the dye "stick" to the eggs, so add a little bit of vinegar to whatever liquid you want to try as an egg dye. You could boil some beets in water and use that to dye your eggs, or use grape juice concentrate the same way. Search the internet for more ideas - there are plenty more out there!
Here's a great worksheet to fill out to help you experiment with the colors of different vegetables.