Writers have long used “winter sky” as a precise color reference—a palette that ranges from pale blue and steely gray to even wintry white—to evoke moods of cold clarity, isolation, or fading light. In some works, it becomes a striking simile: eyes are described as “blue as a winter sky,” lending characters an otherworldly chill and detachment ([1], [2]), while landscapes feature a blue winter sky shifting to gray or white, intensifying the starkness of a frozen environment ([3], [4], [5]). With its mutable hues, the winter sky not only paints an atmospheric backdrop but also mirrors the inner feelings of loss, melancholia, or subdued beauty in the narrative.