For the yellow macaron shells:, powdered sugar (150 g), almond flour (150 g), large egg whites, divided (about 110 g, split into 2 portions of 55 g each), mineral water (37 g), granulated sugar (150 g), small amount of yellow food coloring, For the white macaron shells:, powdered sugar (150 g), almond flour (150 g), large egg whites, divided (about 110 g, split into 2 portions of 55 g each), mineral water (37 g)