What Is A Red, White, Black, And Grey Koi ?

The most common type of koi that is red, black, white, blue and grey is a Goshiki

The vivid Goshiki resembles a Kohaku, but it features delicate, crescent-shaped dark grey patterns on its white skin. In contrast, the darker Kuro Goshiki sometimes exhibits reticulation on its red sections as well. In this variety, the white area is largely covered by large, dim grey reticulation that can appear almost black or dark purple in colour.