How did redditor /u/input36 achieve this amazing coloration?
Bakers, both professional and amateur, offer their guesses. The green is obvious food dye in the dough. But how did s/he achieve the black color? Perhaps by using butter dyed black or a blackened egg wash. Alternatively, it could be powdered activated charcoal or painted chocolate.
/u/input36 eventually answers: laminating the dough. Laminating, in this sense, means carefully folding butter into dough so that the dough has alternating layers of butter and flour. /u/input36 then made sure that the final layer was butter, which s/he then colored black.
Be sure to check out /u/input36’s profile for images of similarly amazing croissants.