#00151D

CSS

:root {
  --black-stallion: #00151d;
  --black-stallion-rgb: 0 21 29;
  --black-stallion-oklch: oklch(0.182 0.034 223.7);
}

.element {
  color: var(--black-stallion);
  background-color: hsl(197 100% 6%);
  border-color: oklch(0.182 0.034 223.7);
}

Tailwind CSS v4

@theme {
  --color-black-stallion: #00151d;
  --color-black-stallion-50: #ebf7fd;
  --color-black-stallion-100: #ddebf1;
  --color-black-stallion-200: #c6d8df;
  --color-black-stallion-300: #a6bbc5;
  --color-black-stallion-400: #8aa3ad;
  --color-black-stallion-500: #6e8c97;
  --color-black-stallion-600: #5d7680;
  --color-black-stallion-700: #4b5e66;
  --color-black-stallion-800: #36454b;
  --color-black-stallion-900: #253034;
  --color-black-stallion-950: #131c1f;
}

SCSS

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