Because black cheeseburgers weren't kooky enough, Burger King is now serving up red cheeseburgers in Japan.

The Aka Burger ("aka" means "red") comes in two varieties - Samurai Beef and Samurai Chicken, both making use of red cheese and red buns.

Tomato powder was added to give the ingredients their angry colour, with the burgers also coming with a red hot sauce made from miso and hot pepper. They go on sale from 3 July.

According to the Wall Street Journal, Burger King claims to have also improved the recipe of its black burgers, which looked pretty intriguing when they arrived last year, but in reality were the stuff of nightmares. The same black buns, cheese and sauce will be used, but now deep fried aubergine has been added. That will solve everything!

Stay tuned for purple, green and blue burgers, and maybe in 2017 some sort of mind-melting rainbow burger.

As sales of fast food sag, the major chains are turning to weird and wonderful limited editions for a PR boost, with KFC having previously created a fried chicken USB stick.