Tororo konbu found in Toyama Prefecture is basically black in color which is used to cover the rice in a lunchbox much like Nori Bento (in which the rice is covered with a very thin layer of bonito shavings seasoned with soy sauce and topped with sheets of nori seaweed) and as a topping for Japanese savory pancakes.
富山県でのとろろ昆布は黒色が基本で、のり弁当の様に弁当のご飯へ敷き詰めたり、お好み焼きのトッピングにも利用されている。