#40001B

CSS

:root {
  --what-we-do-in-the-shadows: #40001b;
  --what-we-do-in-the-shadows-rgb: 64 0 27;
  --what-we-do-in-the-shadows-oklch: oklch(0.24 0.097 2.6);
}

.element {
  color: var(--what-we-do-in-the-shadows);
  background-color: hsl(335 100% 13%);
  border-color: oklch(0.24 0.097 2.6);
}

Tailwind CSS v4

@theme {
  --color-what-we-do-in-the-shadows: #40001b;
  --color-what-we-do-in-the-shadows-50: #ffeaf1;
  --color-what-we-do-in-the-shadows-100: #ffdbe4;
  --color-what-we-do-in-the-shadows-200: #f9c4cf;
  --color-what-we-do-in-the-shadows-300: #e3a3b1;
  --color-what-we-do-in-the-shadows-400: #cf8699;
  --color-what-we-do-in-the-shadows-500: #bb6a80;
  --color-what-we-do-in-the-shadows-600: #9e5a6d;
  --color-what-we-do-in-the-shadows-700: #7f4857;
  --color-what-we-do-in-the-shadows-800: #5e3341;
  --color-what-we-do-in-the-shadows-900: #42232c;
  --color-what-we-do-in-the-shadows-950: #2a121a;
}

SCSS

$what-we-do-in-the-shadows: #40001b;
$what-we-do-in-the-shadows-rgb: 64, 0, 27;
$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);
}