Preheat the oven to 300 F (150 C).
In the bowl of a food processor, combine the powdered sugar, hazelnut powder, and almond powder. Pulse for a few seconds to mix well.
Add the egg whites, almond extract, and a drop of food coloring, and pulse until the mixture is homogeneous.

Shape the dough into balls the size of a walnut and roll them in powdered sugar.
Place them on baking sheets lined with silicone mats or parchment paper.
Bake for 20 minutes.
Let rest for 5 minutes before allowing to cool completely on a rack.