#003A23

CSS

:root {
  --pitch-black-forests: #003a23;
  --pitch-black-forests-rgb: 0 58 35;
  --pitch-black-forests-oklch: oklch(0.307 0.07 159.9);
}

.element {
  color: var(--pitch-black-forests);
  background-color: hsl(156 100% 11%);
  border-color: oklch(0.307 0.07 159.9);
}

Tailwind CSS v4

@theme {
  --color-pitch-black-forests: #003a23;
  --color-pitch-black-forests-50: #e5fcef;
  --color-pitch-black-forests-100: #d4f0e1;
  --color-pitch-black-forests-200: #bbdecb;
  --color-pitch-black-forests-300: #98c3ac;
  --color-pitch-black-forests-400: #7aac90;
  --color-pitch-black-forests-500: #5b9576;
  --color-pitch-black-forests-600: #4e7e64;
  --color-pitch-black-forests-700: #3e6550;
  --color-pitch-black-forests-800: #2d4a39;
  --color-pitch-black-forests-900: #1e3327;
  --color-pitch-black-forests-950: #0e1f15;
}

SCSS

$pitch-black-forests: #003a23;
$pitch-black-forests-rgb: 0, 58, 35;
$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);
}