#0F191E

CSS

:root {
  --black-stallion: #0f191e;
  --black-stallion-rgb: 15 25 30;
  --black-stallion-oklch: oklch(0.206 0.018 230.3);
}

.element {
  color: var(--black-stallion);
  background-color: hsl(200 33% 9%);
  border-color: oklch(0.206 0.018 230.3);
}

Tailwind CSS v4

@theme {
  --color-black-stallion: #0f191e;
  --color-black-stallion-50: #f0f6f9;
  --color-black-stallion-100: #e2e9ed;
  --color-black-stallion-200: #cdd6db;
  --color-black-stallion-300: #afb9bf;
  --color-black-stallion-400: #94a1a7;
  --color-black-stallion-500: #7b8990;
  --color-black-stallion-600: #68747a;
  --color-black-stallion-700: #535c61;
  --color-black-stallion-800: #3c4447;
  --color-black-stallion-900: #292f31;
  --color-black-stallion-950: #171b1d;
}

SCSS

$black-stallion: #0f191e;
$black-stallion-rgb: 15, 25, 30;
$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);
}