#0F1919

CSS

:root {
  --black-stallion: #0f1919;
  --black-stallion-rgb: 15 25 25;
  --black-stallion-oklch: oklch(0.204 0.015 196.1);
}

.element {
  color: var(--black-stallion);
  background-color: hsl(180 25% 8%);
  border-color: oklch(0.204 0.015 196.1);
}

Tailwind CSS v4

@theme {
  --color-black-stallion: #0f1919;
  --color-black-stallion-50: #f1f6f6;
  --color-black-stallion-100: #e3e9e9;
  --color-black-stallion-200: #cdd6d6;
  --color-black-stallion-300: #afbaba;
  --color-black-stallion-400: #95a1a1;
  --color-black-stallion-500: #7c8989;
  --color-black-stallion-600: #697474;
  --color-black-stallion-700: #545d5d;
  --color-black-stallion-800: #3d4444;
  --color-black-stallion-900: #2a2f2f;
  --color-black-stallion-950: #171c1b;
}

SCSS

$black-stallion: #0f1919;
$black-stallion-rgb: 15, 25, 25;
$black-stallion-light: mix(#fff, $black-stallion, 20%);
$black-stallion-dark: mix(#000, $black-stallion, 20%);

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