huelightness

Huelightness is a term used in color theory and digital design to denote the perceptual brightness of a color at a fixed hue. It describes how light or dark a color appears when its hue remains constant while its lightness varies.

The term blends hue and lightness; it is not standard in formal color science but appears in educational contexts to discuss hue-lightness interactions and tonal scales.

In perceptual color spaces, lightness is represented by L* in CIELAB and by L in HSL. Huelightness thus corresponds to those lightness coordinates, though perceptual brightness is context dependent and can differ from physical luminance.

It informs palette design, contrast assessment, and color-matching tasks where hue is kept constant while lightness changes.

Because huelightness is not standardized, terms and numeric values may vary across systems, and the concept risks confusion with luminance and brightness.