Kay Gray was developed by the Wisconsin grape breeder Elmer Swenson c. 1980 and is named after a family friend.
Swenson collected open-pollinated seeds from this vine, and one seedling eventually became Kay Gray.
Because of this, the male parent is unknown, though Swenson suspected it might be a nearby vine of Onaka, an old South Dakota cultivar.
Kay Gray itself is female and requires a pollen source in order to set fruit.
[1] In some environments it can produce an odd flavored wine that is vastly improved by modest levels of blending.