Grey occupies a modest but telling position in the depth-psychological corpus, surfacing at three distinct registers. Most consequentially, it appears as one of the named colours within the alchemical colour-sequence catalogued by Jung in Psychology and Alchemy, where it stands alongside nigredo, albedo, citrinitas, and rubedo as a transitional or liminal tint — registered but not fully theorised, an iridescent remainder that resists resolution into the primary stages. Hillman’s Alchemical Psychology amplifies the broader chromatic field within which grey is implicitly situated: the transit from black through blue to white generates intermediate shades whose psychological valence (melancholy, sobriety, mortification) cannot be exhausted by any single colour-name. Thomas Moore gestures toward this same territory when he affirms that the soul presents itself in ‘all the shades of gray, blue, and black,’ insisting that care of the soul demands attention to its darker colourings rather than their repression. In the mythopoetic register, Kerényi’s account of the Graiai — the Grey Goddesses born grey-haired, whose very name derives from the Greek word for old woman — locates grey in archaic feminine wisdom and the uncanny, linking colour to age, liminality, and chthonic knowledge. Neurobiological texts contribute a purely anatomical usage: the periaqueductal grey, a brainstem structure central to pain modulation and affective regulation. The term thus spans cosmogonic myth, alchemical symbolics, soulful aesthetics, and somatic neuroscience.