#091928

CSS

:root {
  --the-count-s-black: #091928;
  --the-count-s-black-rgb: 9 25 40;
  --the-count-s-black-oklch: oklch(0.208 0.037 248.6);
}

.element {
  color: var(--the-count-s-black);
  background-color: hsl(209 63% 10%);
  border-color: oklch(0.208 0.037 248.6);
}

Tailwind CSS v4

@theme {
  --color-the-count-s-black: #091928;
  --color-the-count-s-black-50: #eef6ff;
  --color-the-count-s-black-100: #dfe9f4;
  --color-the-count-s-black-200: #c9d6e4;
  --color-the-count-s-black-300: #aab9ca;
  --color-the-count-s-black-400: #8ea1b4;
  --color-the-count-s-black-500: #73899e;
  --color-the-count-s-black-600: #627486;
  --color-the-count-s-black-700: #4e5d6b;
  --color-the-count-s-black-800: #38444f;
  --color-the-count-s-black-900: #262f37;
  --color-the-count-s-black-950: #151b22;
}

SCSS

$the-count-s-black: #091928;
$the-count-s-black-rgb: 9, 25, 40;
$the-count-s-black-light: mix(#fff, $the-count-s-black, 20%);
$the-count-s-black-dark: mix(#000, $the-count-s-black, 20%);

.element {
  color: $the-count-s-black;
  box-shadow: 0 0 0 2px rgba($the-count-s-black, 0.35);
}