Dye the Easter Eggs 

1. In a heat-proof bowl, stir together hot water, white vinegar, and food coloring. Add 1 hard-boiled egg. Let it sit until it reaches the desired shade – about 3 minutes. Remove it to a plate. 
2. Repeat the coloring process for the remaining 5 eggs. Allow them to dry completely. 

Prepare the Brioche Dough

1. In the bowl of a stand mixer whisk together warm milk, sugar and yeast. Let the mixture sit for 5 minutes or until the yeast is foamy.
2. Whisk in 3 of the eggs. (Save the last egg for the egg wash.)
3. Add 3 cups flour to the bowl. Mix on low speed using the dough hook attachment. Once the dough has come together into a loose ball, start adding the softened butter – 1 tablespoon at a time. When the dough sticks to the sides of the bowl (usually after adding 3 to 4 tablespoons butter), add another 1/4 cup flour. Continue alternating butter and flour until all of the ingredients have been added. Continue mixing until the dough comes together into a smooth ball – about 2 to 3 minutes.
4. Place the dough into a lightly-oiled boil and cover it with a dampened cloth. Set it  aside in a warm draft-free place. Allow it to rise until doubled in size – about 1 1/2 to 2 hours.
5. Preheat oven to 350ºF. Transfer the dough to a lightly-floured surface. Divide it into 12 equal pies. Roll each piece into a 12-inch long rope. Twist 2 ropes together. Shape the braided rope into a circle. Pinch the seams together – we don’t want the wreath to unwrap in the oven. Place a dyed egg into the center of each wreath. Line 2 large baking sheets with parchment paper.
6. Transfer the wreaths to the prepared baking sheets. Make sure to place them at least 3-inches apart – they will puff up as they bake. In a ramekin, beat remaining egg with a splash of water to create an egg wash. Brush the edges of the wreaths with egg wash, avoiding the dyed egg or the color may bleed onto the dough. Sprinkle the wreaths with rainbow nonpareils.
7. Bake the Easter egg bread for 25 to 28 minutes, or until golden blonde. Allow the wreaths to cool completely on the pan.