hueswhen

Hueswhen is a term used in color theory to describe the temporal dimension of hue. It refers to the set or trajectory of hue values observed for a given scene or stimulus as lighting or viewing conditions change over time.

The term is not part of formal color standards and has limited, often informal usage. It originated in recent discussions among researchers and practitioners who study dynamic color perception, metamerism, and color constancy.

In practice, a hueswhen analysis records color data at successive time points and expresses hue as an angle or category in a chosen color space (for example, hue angle in CIECAM02 or HSV). The analysis accounts for chromatic adaptation, spectral changes in illumination, and scene movement, capturing how a scene’s perceived hue evolves rather than a single static value.

Applications include dynamic lighting design, photography and cinematography workflows, display calibration for changing environments, and color-appearance research. The approach helps anticipate perceptual color shifts in time-sensitive contexts.

Limitations and notes: because there is no standard definition, measurements depend on the observer, instrument, time sampling, and color space chosen. Hueswhen complements but does not replace existing concepts such as color constancy and metamerism.

See also: color constancy, hue, chromatic adaptation, metamerism, color space.