#00311C

CSS

:root {
  --pitch-black-forests: #00311c;
  --pitch-black-forests-rgb: 0 49 28;
  --pitch-black-forests-oklch: oklch(0.276 0.064 158.9);
}

.element {
  color: var(--pitch-black-forests);
  background-color: hsl(154 100% 10%);
  border-color: oklch(0.276 0.064 158.9);
}

Tailwind CSS v4

@theme {
  --color-pitch-black-forests: #00311c;
  --color-pitch-black-forests-50: #e6fbef;
  --color-pitch-black-forests-100: #d6efe1;
  --color-pitch-black-forests-200: #beddcb;
  --color-pitch-black-forests-300: #9cc2ad;
  --color-pitch-black-forests-400: #7eaa91;
  --color-pitch-black-forests-500: #619377;
  --color-pitch-black-forests-600: #527d65;
  --color-pitch-black-forests-700: #416450;
  --color-pitch-black-forests-800: #304939;
  --color-pitch-black-forests-900: #203327;
  --color-pitch-black-forests-950: #101e15;
}

SCSS

$pitch-black-forests: #00311c;
$pitch-black-forests-rgb: 0, 49, 28;
$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);
}