#150503

CSS

:root {
  --dark-matter: #150503;
  --dark-matter-rgb: 21 5 3;
  --dark-matter-oklch: oklch(0.144 0.032 32.9);
}

.element {
  color: var(--dark-matter);
  background-color: hsl(7 75% 5%);
  border-color: oklch(0.144 0.032 32.9);
}

Tailwind CSS v4

@theme {
  --color-dark-matter: #150503;
  --color-dark-matter-50: #fef2ef;
  --color-dark-matter-100: #f2e4e1;
  --color-dark-matter-200: #e2d0cb;
  --color-dark-matter-300: #c7b2ac;
  --color-dark-matter-400: #b19892;
  --color-dark-matter-500: #9a7f79;
  --color-dark-matter-600: #836b66;
  --color-dark-matter-700: #695652;
  --color-dark-matter-800: #4d3e3c;
  --color-dark-matter-900: #362b29;
  --color-dark-matter-950: #211817;
}

SCSS

$dark-matter: #150503;
$dark-matter-rgb: 21, 5, 3;
$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);
}