Citrinitas, the yellowing, is the third stage of the classical four-stage color sequence in alchemy, positioned between the whitening of albedo and the final reddening of rubedo. In the earliest and most complete formulations of the alchemical color scheme, the sequence runs black (nigredo), white (albedo), yellow (citrinitas), and red (rubedo), mapping the progressive perfection of matter from its initial corruption through successive degrees of purification and exaltation. The yellow stage represents the moment of vivification — the point at which the purified white matter begins to receive the animating warmth that will eventually bring it to the fullness of the red perfection.

In the history of alchemical theory, citrinitas occupies an ambiguous position. Some traditions, particularly later ones, collapse the four-stage scheme into three stages by omitting or absorbing the yellowing into either the albedo or the rubedo. When the four-stage scheme is maintained, the yellowing is typically associated with the dawn, with gold in its unfinished state, and with the transition from the lunar, silvery whiteness to the solar, golden redness. The term derives from the Latin citrinus, meaning lemon-colored, and the stage was sometimes associated with the appearance of a yellow or golden hue in the matter within the vessel. The Turba Philosophorum and the Rosarium tradition both reference the color yellow as part of the complete sequence through which the Stone must pass.

In Atalanta Fugiens, Maier treats citrinitas as a transitional moment rather than devoting a full emblem to the yellowing as he does for nigredo and albedo. The yellow stage is most clearly present in the geometric formula of Emblem XXI, where De Jong identifies the triangle as encoding three colors — black, white, and yellow — that precede the red. The body or earth appears in the black color of Saturn, the spirit or water appears in the whiteness of the Moon, and the soul or air appears in the yellow color of the Sun. The triangle must then be transformed into a circle, representing the final unchangeable redness of the completed Stone.

De Jong also identifies citrinitas in Maier's discussion of Laton (electron) in Emblem XI, where the imperfect yellow body composed of gold and silver must be washed white. The yellowing here represents an intermediate state — Laton is neither fully base nor fully perfected, but occupies a transitional position between impurity and purity. The Clangor Buccinae, one of Maier's sources, describes Laton as the imperfect yellow body that must pass through whitening before it can achieve redness. Maier personifies Laton as the goddess Latona, whose blackened face must be washed clean — a vivid dramatization of the progression from yellow imperfection through white purity.

Tilton reads the yellowing into the broader geometric and elemental framework of Emblem XXI, where the soul-as-air phase corresponds to the intermediate vivification between albedo and rubedo. The yellow is the color of the Sun, and the Sun represents the active, masculine, generative principle that must be united with the Moon's passive, feminine receptivity. In the four-element scheme that Maier deploys throughout the Atalanta Fugiens, air (yellow, solar) mediates between water (white, lunar) and fire (red, perfective).

For the non-specialist reader, citrinitas is the alchemical dawn — the moment between the cold whiteness of purification and the full heat of perfection. It is the color of ripening grain, of gold not yet fully refined, of the sun just clearing the horizon. The alchemists recognized it as a sign that the Work was progressing correctly, even if many later writers, impatient with the subtlety of the four-stage scheme, chose to skip directly from white to red.

Meanings Across Registers

De Jong shows that alchemical terms operate simultaneously across material, medical, spiritual, and cosmological dimensions.

Alchemical

The yellowing: a transitional phase between albedo and rubedo where the white matter takes on a golden hue, signaling the approach of perfection.

Medical

Associated with yellow bile and the choleric temperament in its constructive aspect—vital heat that drives metabolism and bodily vigor.

Spiritual

The dawning of solar consciousness; wisdom emerging between the passive receptivity of albedo and the full realization of rubedo.

Cosmological

The dawn and the rising sun; the transitional moment when lunar silver yields to solar gold in the celestial cycle.