#04392F

CSS

:root {
  --pitch-black-forests: #04392f;
  --pitch-black-forests-rgb: 4 57 47;
  --pitch-black-forests-oklch: oklch(0.309 0.055 176.1);
}

.element {
  color: var(--pitch-black-forests);
  background-color: hsl(169 87% 12%);
  border-color: oklch(0.309 0.055 176.1);
}

Tailwind CSS v4

@theme {
  --color-pitch-black-forests: #04392f;
  --color-pitch-black-forests-50: #e5fbf5;
  --color-pitch-black-forests-100: #d5eee8;
  --color-pitch-black-forests-200: #bcdcd4;
  --color-pitch-black-forests-300: #9ac1b7;
  --color-pitch-black-forests-400: #7caa9d;
  --color-pitch-black-forests-500: #5d9285;
  --color-pitch-black-forests-600: #4f7c70;
  --color-pitch-black-forests-700: #3f635a;
  --color-pitch-black-forests-800: #2e4941;
  --color-pitch-black-forests-900: #1f322d;
  --color-pitch-black-forests-950: #0e1e1a;
}

SCSS

$pitch-black-forests: #04392f;
$pitch-black-forests-rgb: 4, 57, 47;
$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);
}