#091A21

CSS

:root {
  --black-stallion: #091a21;
  --black-stallion-rgb: 9 26 33;
  --black-stallion-oklch: oklch(0.207 0.027 227);
}

.element {
  color: var(--black-stallion);
  background-color: hsl(198 57% 8%);
  border-color: oklch(0.207 0.027 227);
}

Tailwind CSS v4

@theme {
  --color-black-stallion: #091a21;
  --color-black-stallion-50: #eef7fb;
  --color-black-stallion-100: #dfeaef;
  --color-black-stallion-200: #c9d7dd;
  --color-black-stallion-300: #aabac2;
  --color-black-stallion-400: #8fa2ab;
  --color-black-stallion-500: #748a94;
  --color-black-stallion-600: #63757d;
  --color-black-stallion-700: #4f5d64;
  --color-black-stallion-800: #394549;
  --color-black-stallion-900: #272f33;
  --color-black-stallion-950: #151c1f;
}

SCSS

$black-stallion: #091a21;
$black-stallion-rgb: 9, 26, 33;
$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);
}