#0B1925

CSS

:root {
  --the-count-s-black: #0b1925;
  --the-count-s-black-rgb: 11 25 37;
  --the-count-s-black-oklch: oklch(0.207 0.031 245.9);
}

.element {
  color: var(--the-count-s-black);
  background-color: hsl(208 54% 9%);
  border-color: oklch(0.207 0.031 245.9);
}

Tailwind CSS v4

@theme {
  --color-the-count-s-black: #0b1925;
  --color-the-count-s-black-50: #eef6fe;
  --color-the-count-s-black-100: #e0e9f2;
  --color-the-count-s-black-200: #cad6e1;
  --color-the-count-s-black-300: #abb9c7;
  --color-the-count-s-black-400: #90a1b0;
  --color-the-count-s-black-500: #76899a;
  --color-the-count-s-black-600: #647482;
  --color-the-count-s-black-700: #505d68;
  --color-the-count-s-black-800: #39444d;
  --color-the-count-s-black-900: #272f35;
  --color-the-count-s-black-950: #151b20;
}

SCSS

$the-count-s-black: #0b1925;
$the-count-s-black-rgb: 11, 25, 37;
$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);
}