The pure color attribute of a color, what we refer to when we say something is "red," "blue," or "green," independent of its lightness or saturation.
Hue is the attribute of a color that distinguishes red from blue, green from yellow. It is the "pure color" quality: what we name when we say a color is cyan, magenta, or orange. In color models, hue is typically represented as an angle on a color wheel, from 0° to 360°, where 0° (and 360°) is red, 120° is green, and 240° is blue.
Hue is one of the three dimensions of color in the HSL, HSV, and OKLCH color models, the others being lightness (or brightness) and saturation (or chroma). All three together fully specify a color; hue alone does not.
Hue is the dimension most responsible for the identity of a color and its emotional associations. When we say a brand is "blue," we're describing its dominant hue. Hue is what determines color relationships (complementary, analogous, triadic), and these relationships are entirely about hue, not about lightness or saturation.
Changing hue dramatically changes how a color is perceived. Shifting a button from blue to green changes its meaning entirely. By contrast, changing only lightness or saturation produces variations of the same color.
HSL/HSV: Hue is expressed as a degree from 0° to 360°. The same hue angle applies across the full range of saturation and lightness.
OKLCH: In OKLCH, hue works the same way (0-360° angle) but is defined in a perceptually uniform space, so hue changes produce more consistent perceived shifts across different lightness levels.
RGB/HEX: Hue is implicit. A specific combination of red, green, and blue channel values produces a given hue, but you can't directly set the hue as a single value. This is why HSL and OKLCH are more intuitive for design work.
220° (blue) to 280° (violet) on a primary color creates a brand refresh with the same lightness and saturationColor is the full description of how a surface appears (hue, saturation, lightness, and context). Hue is just one attribute of color: the pure color quality independent of how light or dark or vivid it is. Pink and dark red share the same hue (red) but differ in lightness and saturation.
Yes. Two colors can share a hue of exactly 220° (blue) but one might be a very light sky blue (high lightness, low saturation) and the other a deep navy (low lightness). They share a hue identity but are dramatically different colors. This is why hue alone is insufficient to describe a color.
Hue rotation is a CSS filter effect (filter: hue-rotate(90deg)) that shifts the hue of all colors in an element by a given angle. It is used for effects and color theming, for example rotating an icon's hue to match a brand color. It shifts every color in the element by the same angle on the color wheel.