Keeping the Russian Easter Tradition alive - coloring eggs in onion shells

Easter is tomorrow and I am coloring the eggs using the onion shells, the same way my mother has been doing for decades. Here is the recipe.

Ingredients:

White Eggs (I use 5-6)
Yellow onion shells (from about 10 big onions or as many as you can get)
Cold water

Preparation:

Put onion shells in a large pot, add cold water and eggs. Make sure there is enough water so eggs and shells are fully submerged. Cook on medium heat until water starts to boil, then reduce heat to medium/medium low and let eggs cook for another 25 minutes. For a darker brown color leave some eggs for another 10 minutes. Take eggs out and let them cool.