The Astounding Broccoli Boy.

Boyce, Frank Cottrell. The Astounding Broccoli Boy. 
September 8th 2015 by Walden Pond Press
ARC from Young Adult Books Central and reviewed there

Rory is bullied by a boy named Grim Komissky, who steals his lunch even though Rory's sister puts super hot sauce on his ham sandwiches. When Grim scarfs down a Wagon Wheel biscuit, he has an allergic reaction and ends up in the hospital. After falling into the water on a class outing, Rory turns bright green, and ends up in the hospital as well, in an isolation unit. There is a cat fever running rampant in London, and everyone is worried about too many people becoming sick and Christmas being canceled. Rory is tested and watched, but he and Grim, aka Tommy-Lee, strike up an uneasy friendship and decide to break out of the hospital and have adventures. Rory is convinced that he has "slightly teleported" and has 200% brain power, and since everyone who has ever been green (e.g. the Hulk, the Green Lantern) has superpowers, he decides that he and Tommy-Lee have them as well. When out and about, they meet the very green Koko Kwok and sneak her into the hospital as well to join in their adventures. They let animals out of the zoo, attempt to see the queen but instead have a lengthy talk with the prince and his baby, and at one point, are mistaken for space aliens! They are tasered and come to at 10 Downing Street, where they confer with the prime minister and manage to help with the cat fever epidemic. We do find out why they turned green, but I won't spoil that.

There is some nice diversity in this: Rory's father is black and his mother white, Koko is part Asian, and Tommy-Lee's real name is Karol, which, as he explains, is a boy's name in Poland. The ensemble cast works nicely through all of their improbable adventures.

This is a very British book, with tea and biscuits, lots of London landmarks, and thinly veiled real British celebrities or government officials. It is goofy in a typically British way, so fans of Roald Dahl, Dave Shelton (A Boy, A Bear, and A Boat) or Michael Lawrence (Jiggy McCue), or anyone who enjoys a good super hero romp, will enjoy this import. Green means GO!