#0F1A26

CSS

:root {
  --the-count-s-black: #0f1a26;
  --the-count-s-black-rgb: 15 26 38;
  --the-count-s-black-oklch: oklch(0.214 0.029 251.3);
}

.element {
  color: var(--the-count-s-black);
  background-color: hsl(211 43% 10%);
  border-color: oklch(0.214 0.029 251.3);
}

Tailwind CSS v4

@theme {
  --color-the-count-s-black: #0f1a26;
  --color-the-count-s-black-50: #f0f6fd;
  --color-the-count-s-black-100: #e1e9f2;
  --color-the-count-s-black-200: #ccd5e1;
  --color-the-count-s-black-300: #adb9c6;
  --color-the-count-s-black-400: #92a0af;
  --color-the-count-s-black-500: #798899;
  --color-the-count-s-black-600: #667381;
  --color-the-count-s-black-700: #525c68;
  --color-the-count-s-black-800: #3b434c;
  --color-the-count-s-black-900: #282f35;
  --color-the-count-s-black-950: #161b20;
}

SCSS

$the-count-s-black: #0f1a26;
$the-count-s-black-rgb: 15, 26, 38;
$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);
}