plenary-css/lib/color.css

plenary: full; complete; entire; absolute; unqualified. All the css functions I don't want to write twice.

@function --lerp-color(--a<color>, --b<color>, --t<number>: --sibling-factor(), --mode: in lch longer hue) {
  result: color-mix(var(--mode), var(--a), var(--b) calc(var(--t) * 100%));
}

@function --set-alpha(--color <color>, --alpha <number>: 0.5) {
  result: hsl(from var(--color) h s l / var(--alpha));
}