#0F191D

CSS

:root {
  --black-stallion: #0f191d;
  --black-stallion-rgb: 15 25 29;
  --black-stallion-oklch: oklch(0.206 0.017 224.7);
}

.element {
  color: var(--black-stallion);
  background-color: hsl(197 32% 9%);
  border-color: oklch(0.206 0.017 224.7);
}

Tailwind CSS v4

@theme {
  --color-black-stallion: #0f191d;
  --color-black-stallion-50: #f0f6f9;
  --color-black-stallion-100: #e2e9ec;
  --color-black-stallion-200: #cdd6da;
  --color-black-stallion-300: #afb9be;
  --color-black-stallion-400: #95a1a6;
  --color-black-stallion-500: #7b898e;
  --color-black-stallion-600: #687479;
  --color-black-stallion-700: #535d60;
  --color-black-stallion-800: #3c4447;
  --color-black-stallion-900: #292f31;
  --color-black-stallion-950: #171b1d;
}

SCSS

$black-stallion: #0f191d;
$black-stallion-rgb: 15, 25, 29;
$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);
}