Begin by placing large eggs in a saucepan and covering them with water, ensuring at least an inch of water above the eggs. Bring the water to a rolling boil over medium-high heat. Once boiling, cover the saucepan, remove it from the heat, and let the eggs sit for 12 minutes. Afterward, transfer the eggs into an ice bath for about 5 minutes until cool to the touch, making peeling easier.

Once the eggs are cool, peel each one gently and slice them in half lengthwise. Carefully remove the yolks and place them in a mixing bowl. Add mayonnaise, Dijon mustard, apple cider vinegar, salt, and pepper to the yolks. Use a fork to mash the mixture until smooth and creamy, creating a tasty filling.

Divide the yolk mixture evenly into three separate bowls. In the first bowl, mix in red food coloring until you reach a vibrant shade. In the second bowl, add blue food coloring to achieve your desired hue. Leave the third bowl plain for the white layer. Stir thoroughly in each bowl.

Fill each egg white with the red yolk mixture, then the white yolk filling, followed by a layer of blue mixture on top for a beautiful patriotic presentation.

Sprinkle crumbled feta cheese over the filled deviled eggs for added flavor and texture. For freshness, chop parsley and scatter it on top. Drizzle with olive oil and serve immediately or chill until ready to enjoy!