#0C1921

CSS

:root {
  --black-stallion: #0c1921;
  --black-stallion-rgb: 12 25 33;
  --black-stallion-oklch: oklch(0.206 0.024 236.7);
}

.element {
  color: var(--black-stallion);
  background-color: hsl(203 47% 9%);
  border-color: oklch(0.206 0.024 236.7);
}

Tailwind CSS v4

@theme {
  --color-black-stallion: #0c1921;
  --color-black-stallion-50: #eff6fb;
  --color-black-stallion-100: #e1e9ef;
  --color-black-stallion-200: #cbd6de;
  --color-black-stallion-300: #adb9c3;
  --color-black-stallion-400: #91a1ab;
  --color-black-stallion-500: #778994;
  --color-black-stallion-600: #65747e;
  --color-black-stallion-700: #515d65;
  --color-black-stallion-800: #3a444a;
  --color-black-stallion-900: #282f33;
  --color-black-stallion-950: #161b1f;
}

SCSS

$black-stallion: #0c1921;
$black-stallion-rgb: 12, 25, 33;
$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);
}