#060708

CSS

:root {
  --black-metal: #060708;
  --black-metal-rgb: 6 7 8;
  --black-metal-oklch: oklch(0.128 0.003 245.8);
}

.element {
  color: var(--black-metal);
  background-color: hsl(210 14% 3%);
  border-color: oklch(0.128 0.003 245.8);
}

Tailwind CSS v4

@theme {
  --color-black-metal: #060708;
  --color-black-metal-50: #f4f5f6;
  --color-black-metal-100: #e7e8e9;
  --color-black-metal-200: #d3d4d6;
  --color-black-metal-300: #b6b7b9;
  --color-black-metal-400: #9d9fa0;
  --color-black-metal-500: #848688;
  --color-black-metal-600: #707273;
  --color-black-metal-700: #595b5c;
  --color-black-metal-800: #414243;
  --color-black-metal-900: #2d2e2f;
  --color-black-metal-950: #1a1b1b;
}

SCSS

$black-metal: #060708;
$black-metal-rgb: 6, 7, 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);
}