#0C2334

CSS

:root {
  --the-count-s-black: #0c2334;
  --the-count-s-black-rgb: 12 35 52;
  --the-count-s-black-oklch: oklch(0.247 0.043 243.2);
}

.element {
  color: var(--the-count-s-black);
  background-color: hsl(206 63% 13%);
  border-color: oklch(0.247 0.043 243.2);
}

Tailwind CSS v4

@theme {
  --color-the-count-s-black: #0c2334;
  --color-the-count-s-black-50: #ebf7ff;
  --color-the-count-s-black-100: #dceaf6;
  --color-the-count-s-black-200: #c6d7e6;
  --color-the-count-s-black-300: #a6bacd;
  --color-the-count-s-black-400: #89a2b7;
  --color-the-count-s-black-500: #6e8aa1;
  --color-the-count-s-black-600: #5d7588;
  --color-the-count-s-black-700: #4a5d6d;
  --color-the-count-s-black-800: #354550;
  --color-the-count-s-black-900: #242f38;
  --color-the-count-s-black-950: #131c22;
}

SCSS

$the-count-s-black: #0c2334;
$the-count-s-black-rgb: 12, 35, 52;
$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);
}