#6B5371

CSS

:root {
  --dr-who: #6b5371;
  --dr-who-rgb: 107 83 113;
  --dr-who-oklch: oklch(0.478 0.056 319.5);
}

.element {
  color: var(--dr-who);
  background-color: hsl(288 15% 38%);
  border-color: oklch(0.478 0.056 319.5);
}

Tailwind CSS v4

@theme {
  --color-dr-who: #6b5371;
  --color-dr-who-50: #fdf0ff;
  --color-dr-who-100: #f1e2f3;
  --color-dr-who-200: #e0cde3;
  --color-dr-who-300: #c5afc9;
  --color-dr-who-400: #ad94b3;
  --color-dr-who-500: #977b9e;
  --color-dr-who-600: #7f6885;
  --color-dr-who-700: #66536b;
  --color-dr-who-800: #4a3c4f;
  --color-dr-who-900: #342a37;
  --color-dr-who-950: #1f1722;
}

SCSS

$dr-who: #6b5371;
$dr-who-rgb: 107, 83, 113;
$dr-who-light: mix(#fff, $dr-who, 20%);
$dr-who-dark: mix(#000, $dr-who, 20%);

.element {
  color: $dr-who;
  box-shadow: 0 0 0 2px rgba($dr-who, 0.35);
}