#060403

CSS

:root {
  --black-metal: #060403;
  --black-metal-rgb: 6 4 3;
  --black-metal-oklch: oklch(0.11 0.007 53.3);
}

.element {
  color: var(--black-metal);
  background-color: hsl(20 33% 2%);
  border-color: oklch(0.11 0.007 53.3);
}

Tailwind CSS v4

@theme {
  --color-black-metal: #060403;
  --color-black-metal-50: #f7f5f3;
  --color-black-metal-100: #eae7e6;
  --color-black-metal-200: #d7d3d1;
  --color-black-metal-300: #bab6b4;
  --color-black-metal-400: #a29d9b;
  --color-black-metal-500: #8a8582;
  --color-black-metal-600: #75716e;
  --color-black-metal-700: #5d5a58;
  --color-black-metal-800: #444240;
  --color-black-metal-900: #2f2d2c;
  --color-black-metal-950: #1c1a19;
}

SCSS

$black-metal: #060403;
$black-metal-rgb: 6, 4, 3;
$black-metal-light: mix(#fff, $black-metal, 20%);
$black-metal-dark: mix(#000, $black-metal, 20%);

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