#041419

CSS

:root {
  --black-stallion: #041419;
  --black-stallion-rgb: 4 20 25;
  --black-stallion-oklch: oklch(0.179 0.025 219.5);
}

.element {
  color: var(--black-stallion);
  background-color: hsl(194 72% 6%);
  border-color: oklch(0.179 0.025 219.5);
}

Tailwind CSS v4

@theme {
  --color-black-stallion: #041419;
  --color-black-stallion-50: #eef7fa;
  --color-black-stallion-100: #dfeaee;
  --color-black-stallion-200: #c9d7dc;
  --color-black-stallion-300: #aabbc1;
  --color-black-stallion-400: #8fa2a9;
  --color-black-stallion-500: #748a92;
  --color-black-stallion-600: #63757b;
  --color-black-stallion-700: #4f5e63;
  --color-black-stallion-800: #394548;
  --color-black-stallion-900: #272f32;
  --color-black-stallion-950: #151c1e;
}

SCSS

$black-stallion: #041419;
$black-stallion-rgb: 4, 20, 25;
$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);
}