#05171A

CSS

:root {
  --black-stallion: #05171a;
  --black-stallion-rgb: 5 23 26;
  --black-stallion-oklch: oklch(0.191 0.025 209.3);
}

.element {
  color: var(--black-stallion);
  background-color: hsl(189 68% 6%);
  border-color: oklch(0.191 0.025 209.3);
}

Tailwind CSS v4

@theme {
  --color-black-stallion: #05171a;
  --color-black-stallion-50: #edf7f9;
  --color-black-stallion-100: #dfeaed;
  --color-black-stallion-200: #c9d7da;
  --color-black-stallion-300: #a9bbbf;
  --color-black-stallion-400: #8ea3a6;
  --color-black-stallion-500: #738b8f;
  --color-black-stallion-600: #627679;
  --color-black-stallion-700: #4e5e61;
  --color-black-stallion-800: #394547;
  --color-black-stallion-900: #273031;
  --color-black-stallion-950: #151c1d;
}

SCSS

$black-stallion: #05171a;
$black-stallion-rgb: 5, 23, 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);
}