#0B392D

CSS

:root {
  --pitch-black-forests: #0b392d;
  --pitch-black-forests-rgb: 11 57 45;
  --pitch-black-forests-oklch: oklch(0.31 0.053 171.5);
}

.element {
  color: var(--pitch-black-forests);
  background-color: hsl(164 68% 13%);
  border-color: oklch(0.31 0.053 171.5);
}

Tailwind CSS v4

@theme {
  --color-pitch-black-forests: #0b392d;
  --color-pitch-black-forests-50: #e7faf4;
  --color-pitch-black-forests-100: #d7eee6;
  --color-pitch-black-forests-200: #bedcd2;
  --color-pitch-black-forests-300: #9cc1b5;
  --color-pitch-black-forests-400: #7fa99a;
  --color-pitch-black-forests-500: #619282;
  --color-pitch-black-forests-600: #527b6e;
  --color-pitch-black-forests-700: #426358;
  --color-pitch-black-forests-800: #2f493f;
  --color-pitch-black-forests-900: #20322c;
  --color-pitch-black-forests-950: #101e19;
}

SCSS

$pitch-black-forests: #0b392d;
$pitch-black-forests-rgb: 11, 57, 45;
$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);
}