There are so many colors of koi to make your pond and collection visually appealing and diverse. There are 13 recognized classifications, which are based on color, pattern, and scale type. Occasionally, new color and pattern combinations will occur based on breeding.
Go-Sanke is definitely the most popular variety, with Kohaku, Showa Sanke, and Taisho Sanke as the members of this group. These are the most commonly found in most collectors’ ponds.
Maruzome Kiwa is when the edge of the red goes along the scales into a circular shape. The trailing edge is called Sashi and is a good indicator of whether the koi is still developing its color or is complete.
Sandan Kohaku has three distinct red patterns and is also called a three-step kohaku. Sandan is Japanese for three, hence the three red patterns. This classic pattern makes for a nice fish with a beautiful tail tube and conformation.
Yondan Kohaku is a four-step koi with a more interesting pattern. There is a white cloudiness on the head and shoulders that resembles a costia infection.
Maurten Kohaku has a round beni on its head, the maruten designation. It is a very full pattern, and the koi has a nice tail stop.
Taisho Sanke has an understated elegance appreciated by many koi keepers. The sumi can be placed on the white skin, called Tsubo Sumi, or can appear on the beni, the Kasane Sumi.
Doitsu Sanke is a fish without scales, which makes for sharp edging, called kiwa, and attractive coloring.
Gin Rin Sanke is almost too perfect looking to be real. The sumi steps are arranged like stepping stones, which is striking.
Sanke typically have nice underlying kohaku patterns with accents of sumi on the shoulders. Confirmation is everything in this variety, and black should not appear below the lateral line.
Showa Sanke has a clean pattern free of flecks of sumi. The sumi should join on the head. There is also a nice underlying kohaku pattern.
Tancho Showa has beni only on its head. This uncommon koi has gin rin scaling and shines because of its skin quality, which starts with a healthy white base.
Kindai Showa is a newer style of showa. It has less sumi, or black, than older varieties and its full body makes the fins appear slightly undersized. This showa features black pectoral fin joints, or motoguro, and an interesting head pattern where sumi comes through to form a nice menware / hachiware pattern.