#050909

CSS

:root {
  --black-metal: #050909;
  --black-metal-rgb: 5 9 9;
  --black-metal-oklch: oklch(0.134 0.008 196.2);
}

.element {
  color: var(--black-metal);
  background-color: hsl(180 29% 3%);
  border-color: oklch(0.134 0.008 196.2);
}

Tailwind CSS v4

@theme {
  --color-black-metal: #050909;
  --color-black-metal-50: #f3f6f6;
  --color-black-metal-100: #e5e9e9;
  --color-black-metal-200: #d0d5d5;
  --color-black-metal-300: #b3b9b9;
  --color-black-metal-400: #99a0a0;
  --color-black-metal-500: #808888;
  --color-black-metal-600: #6d7373;
  --color-black-metal-700: #575c5c;
  --color-black-metal-800: #3f4343;
  --color-black-metal-900: #2c2e2e;
  --color-black-metal-950: #191b1b;
}

SCSS

$black-metal: #050909;
$black-metal-rgb: 5, 9, 9;
$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);
}