#160405

CSS

:root {
  --dark-matter: #160405;
  --dark-matter-rgb: 22 4 5;
  --dark-matter-oklch: oklch(0.143 0.036 17.9);
}

.element {
  color: var(--dark-matter);
  background-color: hsl(357 69% 5%);
  border-color: oklch(0.143 0.036 17.9);
}

Tailwind CSS v4

@theme {
  --color-dark-matter: #160405;
  --color-dark-matter-50: #fff1f1;
  --color-dark-matter-100: #f4e3e3;
  --color-dark-matter-200: #e3cfce;
  --color-dark-matter-300: #c9b1b0;
  --color-dark-matter-400: #b39696;
  --color-dark-matter-500: #9d7d7d;
  --color-dark-matter-600: #846a6a;
  --color-dark-matter-700: #6a5555;
  --color-dark-matter-800: #4e3e3e;
  --color-dark-matter-900: #362a2b;
  --color-dark-matter-950: #211818;
}

SCSS

$dark-matter: #160405;
$dark-matter-rgb: 22, 4, 5;
$dark-matter-light: mix(#fff, $dark-matter, 20%);
$dark-matter-dark: mix(#000, $dark-matter, 20%);

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