#131919

CSS

:root {
  --black-stallion: #131919;
  --black-stallion-rgb: 19 25 25;
  --black-stallion-oklch: oklch(0.207 0.009 196.5);
}

.element {
  color: var(--black-stallion);
  background-color: hsl(180 14% 9%);
  border-color: oklch(0.207 0.009 196.5);
}

Tailwind CSS v4

@theme {
  --color-black-stallion: #131919;
  --color-black-stallion-50: #f2f6f6;
  --color-black-stallion-100: #e5e9e9;
  --color-black-stallion-200: #d0d5d5;
  --color-black-stallion-300: #b2b9b9;
  --color-black-stallion-400: #99a0a0;
  --color-black-stallion-500: #808888;
  --color-black-stallion-600: #6c7373;
  --color-black-stallion-700: #565c5c;
  --color-black-stallion-800: #3f4343;
  --color-black-stallion-900: #2b2f2e;
  --color-black-stallion-950: #191b1b;
}

SCSS

$black-stallion: #131919;
$black-stallion-rgb: 19, 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);
}