#060503

CSS

:root {
  --black-metal: #060503;
  --black-metal-rgb: 6 5 3;
  --black-metal-oklch: oklch(0.115 0.008 88.3);
}

.element {
  color: var(--black-metal);
  background-color: hsl(40 33% 2%);
  border-color: oklch(0.115 0.008 88.3);
}

Tailwind CSS v4

@theme {
  --color-black-metal: #060503;
  --color-black-metal-50: #f6f5f3;
  --color-black-metal-100: #e9e8e5;
  --color-black-metal-200: #d5d4d0;
  --color-black-metal-300: #b9b7b3;
  --color-black-metal-400: #a09e99;
  --color-black-metal-500: #888680;
  --color-black-metal-600: #73716d;
  --color-black-metal-700: #5c5b57;
  --color-black-metal-800: #43423f;
  --color-black-metal-900: #2f2e2c;
  --color-black-metal-950: #1b1a19;
}

SCSS

$black-metal: #060503;
$black-metal-rgb: 6, 5, 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);
}