All grasshoppers are green, right?
No. Just as not all swans are black.
http://voices.nationalgeographic.com/2013/06/14/the-pink-grasshopper-no-its-not-a-cocktail/
http://voices.nationalgeographic.com/2013/06/14/the-pink-grasshopper-no-its-not-a-cocktail
we have some in alarming yellow and black, or red and black.