This mutation appeared in Holland in Piet Verhijde’s Aviary in 2004 after crossing a pair of green fischeri x lutino. One of its two main characteristics is the dilution of the chest, from the usual green color of the wild form to a very characteristic dark yellow. The other one is an increase of eumelanin in the bird's wings, leaving the mantle normal in color (as such, one can see a paler tone when compared to the wing color), a feature that seems to draw a V on back of the bird between the wings and mantle by the difference in color tone. Due to this increase of eumelanin, it was decided to call this mutation euwing which means "increase eumelanin in the wings" (increase of eumelanin in the wings)