#020703

CSS

:root {
  --black-metal: #020703;
  --black-metal-rgb: 2 7 3;
  --black-metal-oklch: oklch(0.118 0.019 151.2);
}

.element {
  color: var(--black-metal);
  background-color: hsl(132 56% 2%);
  border-color: oklch(0.118 0.019 151.2);
}

Tailwind CSS v4

@theme {
  --color-black-metal: #020703;
  --color-black-metal-50: #f1f7f2;
  --color-black-metal-100: #e3eae5;
  --color-black-metal-200: #ced7d0;
  --color-black-metal-300: #b0bab3;
  --color-black-metal-400: #97a299;
  --color-black-metal-500: #7d8a80;
  --color-black-metal-600: #6a756c;
  --color-black-metal-700: #555d56;
  --color-black-metal-800: #3e443f;
  --color-black-metal-900: #2b2f2b;
  --color-black-metal-950: #181c19;
}

SCSS

$black-metal: #020703;
$black-metal-rgb: 2, 7, 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);
}