In a large mixing bowl, combine the all-purpose flour, yeast, sugar, and salt. Gradually pour in warm water heated to about 110°F (43°C), mixing until a dough forms. Knead the dough on a floured surface for 8-10 minutes until smooth and elastic.

Shape the dough into a ball and place it in a lightly greased bowl. Cover with a towel or plastic wrap and let it rise in a warm place for 1-2 hours until doubled in size.

Gently punch down the dough, divide it into two portions, and knead red and black food coloring into each until vibrant.

Roll each colored dough into ¼ inch thick rectangles. Layer the red on top of the black, and twist the two layers together to form a loaf. Pinch the ends to seal.

Transfer the twisted loaf into a greased baking pan, cover with a towel, and let it rise for another 30 minutes while preheating the oven to 350°F (175°C).

Bake the loaf for about 30 minutes until golden brown and hollow when tapped.

Remove the loaf from the oven, cool in the pan for 10 minutes, then transfer it to a wire rack to cool completely.