#00271A

CSS

:root {
  --pitch-black-forests: #00271a;
  --pitch-black-forests-rgb: 0 39 26;
  --pitch-black-forests-oklch: oklch(0.242 0.05 165.9);
}

.element {
  color: var(--pitch-black-forests);
  background-color: hsl(160 100% 8%);
  border-color: oklch(0.242 0.05 165.9);
}

Tailwind CSS v4

@theme {
  --color-pitch-black-forests: #00271a;
  --color-pitch-black-forests-50: #e8faf2;
  --color-pitch-black-forests-100: #d9eee5;
  --color-pitch-black-forests-200: #c1dcd0;
  --color-pitch-black-forests-300: #9fc0b2;
  --color-pitch-black-forests-400: #83a898;
  --color-pitch-black-forests-500: #66917e;
  --color-pitch-black-forests-600: #577b6b;
  --color-pitch-black-forests-700: #456256;
  --color-pitch-black-forests-800: #32483e;
  --color-pitch-black-forests-900: #22322a;
  --color-pitch-black-forests-950: #111e18;
}

SCSS

$pitch-black-forests: #00271a;
$pitch-black-forests-rgb: 0, 39, 26;
$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);
}