#00151A

CSS

:root {
  --black-stallion: #00151a;
  --black-stallion-rgb: 0 21 26;
  --black-stallion-oklch: oklch(0.18 0.032 213.8);
}

.element {
  color: var(--black-stallion);
  background-color: hsl(192 100% 5%);
  border-color: oklch(0.18 0.032 213.8);
}

Tailwind CSS v4

@theme {
  --color-black-stallion: #00151a;
  --color-black-stallion-50: #ecf8fb;
  --color-black-stallion-100: #ddebef;
  --color-black-stallion-200: #c6d8dd;
  --color-black-stallion-300: #a6bcc2;
  --color-black-stallion-400: #8aa4aa;
  --color-black-stallion-500: #6f8c93;
  --color-black-stallion-600: #5e767c;
  --color-black-stallion-700: #4b5f63;
  --color-black-stallion-800: #364549;
  --color-black-stallion-900: #253032;
  --color-black-stallion-950: #131c1e;
}

SCSS

$black-stallion: #00151a;
$black-stallion-rgb: 0, 21, 26;
$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);
}