Hue
The attribute that places a color on the spectrum — red, orange, yellow, green, blue, violet — independent of how light or saturated it is.
Example usage
“Keep the hue fixed across all five surface colors and vary only lightness — that’s what keeps the panels feeling like one material.”
Editor’s note
Hue is what civilians mean by “color,” so using it precisely is the cheapest upgrade in design crit: “shift the hue toward green” names one dial, “make it more minty” spins three at once. Mind the tooling, though — HSL’s hue wheel is perceptually lumpy, so equal hue steps don’t look equal (OKLCH’s do). A palette survives almost any adjustment to saturation and lightness; move a hue and you’ve touched the brand.