This is an easy and fun thing to do. Just combine 1 cup of hot water with 1/2 teaspoon of white vinegar and several drops of food coloring. Some people like to experiment with natural substances other than food coloring. For example, you can make green eggs (use boiled spinach leaves), yellow eggs (boiled yellow onion skins), lavender eggs (purple grape juice or blueberries), or pink ones (beets or cranberry juice). Also try using various spices such as turmeric or paprika. Just make sure you use edible stuff to make your dye.