#043725

CSS

:root {
  --pitch-black-forests: #043725;
  --pitch-black-forests-rgb: 4 55 37;
  --pitch-black-forests-oklch: oklch(0.299 0.061 163.6);
}

.element {
  color: var(--pitch-black-forests);
  background-color: hsl(159 86% 12%);
  border-color: oklch(0.299 0.061 163.6);
}

Tailwind CSS v4

@theme {
  --color-pitch-black-forests: #043725;
  --color-pitch-black-forests-50: #e6fbf1;
  --color-pitch-black-forests-100: #d6efe3;
  --color-pitch-black-forests-200: #bdddce;
  --color-pitch-black-forests-300: #9bc2b0;
  --color-pitch-black-forests-400: #7daa95;
  --color-pitch-black-forests-500: #5f937b;
  --color-pitch-black-forests-600: #517d68;
  --color-pitch-black-forests-700: #406453;
  --color-pitch-black-forests-800: #2f493c;
  --color-pitch-black-forests-900: #203329;
  --color-pitch-black-forests-950: #0f1e17;
}

SCSS

$pitch-black-forests: #043725;
$pitch-black-forests-rgb: 4, 55, 37;
$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);
}