#090705

CSS

:root {
  --black-metal: #090705;
  --black-metal-rgb: 9 7 5;
  --black-metal-oklch: oklch(0.13 0.007 71.9);
}

.element {
  color: var(--black-metal);
  background-color: hsl(30 29% 3%);
  border-color: oklch(0.13 0.007 71.9);
}

Tailwind CSS v4

@theme {
  --color-black-metal: #090705;
  --color-black-metal-50: #f6f5f3;
  --color-black-metal-100: #e9e7e5;
  --color-black-metal-200: #d6d4d1;
  --color-black-metal-300: #bab7b3;
  --color-black-metal-400: #a19e9a;
  --color-black-metal-500: #898581;
  --color-black-metal-600: #74716d;
  --color-black-metal-700: #5d5a57;
  --color-black-metal-800: #444240;
  --color-black-metal-900: #2f2d2c;
  --color-black-metal-950: #1b1a19;
}

SCSS

$black-metal: #090705;
$black-metal-rgb: 9, 7, 5;
$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);
}