#00151C

CSS

:root {
  --black-stallion: #00151c;
  --black-stallion-rgb: 0 21 28;
  --black-stallion-oklch: oklch(0.181 0.033 220.6);
}

.element {
  color: var(--black-stallion);
  background-color: hsl(195 100% 5%);
  border-color: oklch(0.181 0.033 220.6);
}

Tailwind CSS v4

@theme {
  --color-black-stallion: #00151c;
  --color-black-stallion-50: #ecf7fc;
  --color-black-stallion-100: #ddebf0;
  --color-black-stallion-200: #c6d8df;
  --color-black-stallion-300: #a6bcc4;
  --color-black-stallion-400: #8aa3ac;
  --color-black-stallion-500: #6e8c96;
  --color-black-stallion-600: #5e767f;
  --color-black-stallion-700: #4b5f65;
  --color-black-stallion-800: #36454a;
  --color-black-stallion-900: #253033;
  --color-black-stallion-950: #131c1f;
}

SCSS

$black-stallion: #00151c;
$black-stallion-rgb: 0, 21, 28;
$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);
}