#0B191F

CSS

:root {
  --black-stallion: #0b191f;
  --black-stallion-rgb: 11 25 31;
  --black-stallion-oklch: oklch(0.204 0.023 227.3);
}

.element {
  color: var(--black-stallion);
  background-color: hsl(198 48% 8%);
  border-color: oklch(0.204 0.023 227.3);
}

Tailwind CSS v4

@theme {
  --color-black-stallion: #0b191f;
  --color-black-stallion-50: #eff7fa;
  --color-black-stallion-100: #e1e9ee;
  --color-black-stallion-200: #cbd6dc;
  --color-black-stallion-300: #acbac1;
  --color-black-stallion-400: #91a1a9;
  --color-black-stallion-500: #778a92;
  --color-black-stallion-600: #65747c;
  --color-black-stallion-700: #505d63;
  --color-black-stallion-800: #3a4448;
  --color-black-stallion-900: #282f32;
  --color-black-stallion-950: #161c1e;
}

SCSS

$black-stallion: #0b191f;
$black-stallion-rgb: 11, 25, 31;
$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);
}