NOTE: if using a food processor for both colors of dough, follow these steps in order (i.e., make the orange dough first), since the food coloring for the black dough will change the color of the orange dough.
Make a mound in 1/2 of the flour and create a well in the top of the mound. Add 2 eggs, 1/2 tablespoon of olive oil, tomato paste, and 1/2 teaspoon of kosher salt to the well. Knead the ingredients together until fully blended. Wrap in plastic wrap and allow to rest at room temperature for at least 30 minutes.
NOTES: 1) a food processor is highly recommendedfor making the "black" pasta, but the next step can be done by hand; 2) this small amount of cocoa doesn't make the pasta taste like chocolate, but increasing the quantity will.
Add remaining flour, 2 eggs, 1/2 tablespoon of olive oil, dark cocoa, and 1/2 teaspoon of kosher salt to food processor. Blend for a few seconds.
Add 4 drops each of green, blue, and red food coloring to food processor. Blend for about a minute. Add 4 more drops of green, blue, and red food coloring and blend for another minute. Add equal portions of food coloring as desired to deepen the dark color.
Remove dough from food processor. Dust work area with flour. Knead the ingredients together until colors are fully blended. Wrap in plastic wrap and allow to rest at room temperature for at least 30 minutes.
Roll dough flat and form into large rectangular strips. Cut by hand or use a pasta roller.
Add cut pasta to the boiling water in small batches and cook for 2-3 minutes each. Remove from water with strainer to keep the hot water boiling. Place in collander to drain. Continue until all the pasta is cooked.
Blend the orange and black pasta together in a bowl and serve.