#370113

CSS

:root {
  --what-we-do-in-the-shadows: #370113;
  --what-we-do-in-the-shadows-rgb: 55 1 19;
  --what-we-do-in-the-shadows-oklch: oklch(0.218 0.085 7.2);
}

.element {
  color: var(--what-we-do-in-the-shadows);
  background-color: hsl(340 96% 11%);
  border-color: oklch(0.218 0.085 7.2);
}

Tailwind CSS v4

@theme {
  --color-what-we-do-in-the-shadows: #370113;
  --color-what-we-do-in-the-shadows-50: #ffecf0;
  --color-what-we-do-in-the-shadows-100: #ffdde2;
  --color-what-we-do-in-the-shadows-200: #f6c6cc;
  --color-what-we-do-in-the-shadows-300: #dfa6ae;
  --color-what-we-do-in-the-shadows-400: #ca8995;
  --color-what-we-do-in-the-shadows-500: #b66e7c;
  --color-what-we-do-in-the-shadows-600: #9a5d69;
  --color-what-we-do-in-the-shadows-700: #7b4a54;
  --color-what-we-do-in-the-shadows-800: #5b363e;
  --color-what-we-do-in-the-shadows-900: #40252b;
  --color-what-we-do-in-the-shadows-950: #291318;
}

SCSS

$what-we-do-in-the-shadows: #370113;
$what-we-do-in-the-shadows-rgb: 55, 1, 19;
$what-we-do-in-the-shadows-light: mix(#fff, $what-we-do-in-the-shadows, 20%);
$what-we-do-in-the-shadows-dark: mix(#000, $what-we-do-in-the-shadows, 20%);

.element {
  color: $what-we-do-in-the-shadows;
  box-shadow: 0 0 0 2px rgba($what-we-do-in-the-shadows, 0.35);
}