Burger Friday is on vacation, soaking up some fall color. On that note, here's some burger color, from Burger King in Japan. Behold two variations on the "Kuro" burger, featuring black buns, black sauce and black cheese (kuro is black in Japanese).

The ingredients are tinted with bamboo charcoal and squid ink, and prices start at the equivalent of $4.

According to Forbes, Burger King is offering the novelty burger to celebrate its five-year anniversary in Japan, and the response has been huge. "As many as half the customers are ordering the trendy new item off the menu at Burger King outlets," notes Forbes.

Naturally, McDonald's is getting in on the action, offering a Halloween-themed "Spooky" burger. "Some customers, however have termed the imitation 'niban senji,' the popular Japanese expression denoting second-best," writes Forbes.

(Photo: Burger King employee Rumi Sekine with the Kuro Pearl burger on the left, and the Kurl Diamond burger on the right, from the Associated Press).

Burger Friday returns Oct. 24.