Function generateNeutralScale

packages/ui/src/theme/color.ts:171–216

(seed: HexColor, isDark: boolean, ink?: HexColor)

}

export function generateNeutralScale(seed: HexColor, isDark: boolean, ink?: HexColor): HexColor[] {
  if (ink) {
    const base = hexToOklch(seed)
    const lift = (tone: number) =>
      oklchToHex({
        l: base.l + (1 - base.l) * tone,
        c: base.c * Math.max(0, 1 - tone),
        h: base.h,
      })
    const sink = (tone: number) =>
      oklchToHex({
        l: base.l * (1 - tone),
        c: base.c * Math.max(0, 1 - tone * (isDark ? 0.12 : 0.3)),
        h: base.h,
      })
    const bg = isDark
      ? sink(clamp(0.19 + Math.max(0, base.l - 0.12) * 0.33 + base.c * 1.95, 0.17, 0.27))
      : base.l < 0.82
        ? lift(0.86)
        : lift(clamp(0.1 + base.c * 3.2 + Math.max(0, 0.95 - base.l) * 0.35, 0.1, 0.28))
    const steps = isDark
      ? [0, 0.018, 0.039, 0.064, 0.097, 0.143, 0.212, 0.31, 0.46, 0.649, 0.845, 0.984]
      : [0, 0.022, 0.042, 0.068, 0.102, 0.146, 0.208, 0.296, 0.432, 0.61, 0.81, 0.965]
    return steps.map((step) => mixColors(bg, ink, step))
  }

  const base = hexToOklch(seed)
  const scale: HexColor[] = []
  const neutralChroma = Math.min(base.c, isDark ? 0.068 : 0.04)

  const lightSteps = isDark
    ? [0.138, 0.156, 0.178, 0.202, 0.232, 0.272, 0.326, 0.404, clamp(base.l * 0.83, 0.43, 0.55), 0.596, 0.719, 0.956]
    : [0.991, 0.979, 0.964, 0.946, 0.931, 0.913, 0.891, 0.83, base.l, 0.617, 0.542, 0.205]

  for (let i = 0; i < 12; i++) {
    scale.push(
      oklchToHex({
        l: lightSteps[i],
        c: neutralChroma,
        h: base.h,
      }),
    )
  }

  return scale
}

export function generateAlphaScale(scale: HexColor[], isDark: boolean): HexColor[] {
  const alphas = isDark