#00271D

CSS

:root {
  --pitch-black-forests: #00271d;
  --pitch-black-forests-rgb: 0 39 29;
  --pitch-black-forests-oklch: oklch(0.243 0.047 171.4);
}

.element {
  color: var(--pitch-black-forests);
  background-color: hsl(165 100% 8%);
  border-color: oklch(0.243 0.047 171.4);
}

Tailwind CSS v4

@theme {
  --color-pitch-black-forests: #00271d;
  --color-pitch-black-forests-50: #e8faf4;
  --color-pitch-black-forests-100: #d9ede6;
  --color-pitch-black-forests-200: #c1dbd2;
  --color-pitch-black-forests-300: #9fc0b5;
  --color-pitch-black-forests-400: #83a89b;
  --color-pitch-black-forests-500: #669182;
  --color-pitch-black-forests-600: #577a6e;
  --color-pitch-black-forests-700: #456258;
  --color-pitch-black-forests-800: #324840;
  --color-pitch-black-forests-900: #22322c;
  --color-pitch-black-forests-950: #111e19;
}

SCSS

$pitch-black-forests: #00271d;
$pitch-black-forests-rgb: 0, 39, 29;
$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);
}