#0D090A

CSS

:root {
  --black-sheep: #0d090a;
  --black-sheep-rgb: 13 9 10;
  --black-sheep-oklch: oklch(0.146 0.007 0.9);
}

.element {
  color: var(--black-sheep);
  background-color: hsl(345 18% 4%);
  border-color: oklch(0.146 0.007 0.9);
}

Tailwind CSS v4

@theme {
  --color-black-sheep: #0d090a;
  --color-black-sheep-50: #f7f4f5;
  --color-black-sheep-100: #eae7e7;
  --color-black-sheep-200: #d7d3d4;
  --color-black-sheep-300: #bbb6b7;
  --color-black-sheep-400: #a29d9e;
  --color-black-sheep-500: #8b8486;
  --color-black-sheep-600: #757071;
  --color-black-sheep-700: #5e595a;
  --color-black-sheep-800: #454142;
  --color-black-sheep-900: #2f2d2e;
  --color-black-sheep-950: #1c1a1a;
}

SCSS

$black-sheep: #0d090a;
$black-sheep-rgb: 13, 9, 10;
$black-sheep-light: mix(#fff, $black-sheep, 20%);
$black-sheep-dark: mix(#000, $black-sheep, 20%);

.element {
  color: $black-sheep;
  box-shadow: 0 0 0 2px rgba($black-sheep, 0.35);
}