#003A30

CSS

:root {
  --pitch-black-forests: #003a30;
  --pitch-black-forests-rgb: 0 58 48;
  --pitch-black-forests-oklch: oklch(0.312 0.058 176.9);
}

.element {
  color: var(--pitch-black-forests);
  background-color: hsl(170 100% 11%);
  border-color: oklch(0.312 0.058 176.9);
}

Tailwind CSS v4

@theme {
  --color-pitch-black-forests: #003a30;
  --color-pitch-black-forests-50: #e5fbf5;
  --color-pitch-black-forests-100: #d4efe8;
  --color-pitch-black-forests-200: #bbddd4;
  --color-pitch-black-forests-300: #98c2b8;
  --color-pitch-black-forests-400: #7aaa9e;
  --color-pitch-black-forests-500: #5a9385;
  --color-pitch-black-forests-600: #4d7c71;
  --color-pitch-black-forests-700: #3d645a;
  --color-pitch-black-forests-800: #2c4941;
  --color-pitch-black-forests-900: #1e332d;
  --color-pitch-black-forests-950: #0d1e1a;
}

SCSS

$pitch-black-forests: #003a30;
$pitch-black-forests-rgb: 0, 58, 48;
$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);
}