#030908

CSS

:root {
  --black-metal: #030908;
  --black-metal-rgb: 3 9 8;
  --black-metal-oklch: oklch(0.131 0.013 185.2);
}

.element {
  color: var(--black-metal);
  background-color: hsl(170 50% 2%);
  border-color: oklch(0.131 0.013 185.2);
}

Tailwind CSS v4

@theme {
  --color-black-metal: #030908;
  --color-black-metal-50: #f1f6f6;
  --color-black-metal-100: #e3e9e8;
  --color-black-metal-200: #ced6d5;
  --color-black-metal-300: #b0bab8;
  --color-black-metal-400: #96a19f;
  --color-black-metal-500: #7d8987;
  --color-black-metal-600: #6a7472;
  --color-black-metal-700: #555d5b;
  --color-black-metal-800: #3e4443;
  --color-black-metal-900: #2a2f2e;
  --color-black-metal-950: #181b1b;
}

SCSS

$black-metal: #030908;
$black-metal-rgb: 3, 9, 8;
$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);
}