Hikari utsuri are Koi of Showa Utsurimono group (Showa Sanshoku, Shiro Utsuri, and Hi Utsuri, etc.) displaying "Hikari (luster or glitter)," and include "Kin Showa (with lustrous gold color)," "Gin Shiro Utsuri (with platinum sheen)," and "Kin Ki Utsuri (literally 'golden yellow Utsuri')."
The point of appreciating this group is of course the intensity of the Hikari, the very characteristic of the Hikarimono group.
Their markings are similar to those of Showa Sanshoku and Utsurimono group mentioned before. The tone of gold and Sumi is deeper, the better. However, there is an intricate aspect which we have to pay close attention. Both Hikari and Sumi pigment have a tendency to cancel each other -- most Koi with strong Hikari have deep Sumi. Consequently, Koi having strong Hikari and firm Sumi at the same time are very rare.