#0D3A21

CSS

:root {
  --pitch-black-forests: #0d3a21;
  --pitch-black-forests-rgb: 13 58 33;
  --pitch-black-forests-oklch: oklch(0.311 0.066 154.8);
}

.element {
  color: var(--pitch-black-forests);
  background-color: hsl(147 63% 14%);
  border-color: oklch(0.311 0.066 154.8);
}

Tailwind CSS v4

@theme {
  --color-pitch-black-forests: #0d3a21;
  --color-pitch-black-forests-50: #e7fbee;
  --color-pitch-black-forests-100: #d7efdf;
  --color-pitch-black-forests-200: #beddc9;
  --color-pitch-black-forests-300: #9cc2aa;
  --color-pitch-black-forests-400: #80aa8d;
  --color-pitch-black-forests-500: #629373;
  --color-pitch-black-forests-600: #537d61;
  --color-pitch-black-forests-700: #42644e;
  --color-pitch-black-forests-800: #304937;
  --color-pitch-black-forests-900: #213326;
  --color-pitch-black-forests-950: #101e14;
}

SCSS

$pitch-black-forests: #0d3a21;
$pitch-black-forests-rgb: 13, 58, 33;
$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);
}