Definition of "whiteless"

[…] The whiteless blue of heaven / Comes down to meet the greenless gray of earth— / And compasses her dream.

1897, Emerson Hough, The Cowboy (originally published as The Story of the Cowboy), New York: The Brampton Society, 1908, Chapter 13, p. 262,[]

In those grave, whiteless eyes and sad small mouth live the eternal sorrows and joys and the whole destiny of man.

1933, Robert Byron, First Russia, Then Tibet, Part I, Chapter 7, Early Russian Painting

The black beard which fanned out across the neck of his stillsuit hood like a wild delta contained flecks of grey, but his eyes carried that same whiteless intensity they’d presented to her on their first encounter in the desert.

1976, Frank Herbert, Children of Dune‎