#003622

CSS

:root {
  --pitch-black-forests: #003622;
  --pitch-black-forests-rgb: 0 54 34;
  --pitch-black-forests-oklch: oklch(0.294 0.065 161.8);
}

.element {
  color: var(--pitch-black-forests);
  background-color: hsl(158 100% 11%);
  border-color: oklch(0.294 0.065 161.8);
}

Tailwind CSS v4

@theme {
  --color-pitch-black-forests: #003622;
  --color-pitch-black-forests-50: #e5fbf0;
  --color-pitch-black-forests-100: #d5efe2;
  --color-pitch-black-forests-200: #bcddcd;
  --color-pitch-black-forests-300: #9ac2ae;
  --color-pitch-black-forests-400: #7cab93;
  --color-pitch-black-forests-500: #5d9479;
  --color-pitch-black-forests-600: #507d66;
  --color-pitch-black-forests-700: #3f6452;
  --color-pitch-black-forests-800: #2e493b;
  --color-pitch-black-forests-900: #1f3328;
  --color-pitch-black-forests-950: #0f1f16;
}

SCSS

$pitch-black-forests: #003622;
$pitch-black-forests-rgb: 0, 54, 34;
$pitch-black-forests-light: mix(#fff, $pitch-black-forests, 20%);
$pitch-black-forests-dark: mix(#000, $pitch-black-forests, 20%);

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