#10311D

CSS

:root {
  --pitch-black-forests: #10311d;
  --pitch-black-forests-rgb: 16 49 29;
  --pitch-black-forests-oklch: oklch(0.282 0.054 154.3);
}

.element {
  color: var(--pitch-black-forests);
  background-color: hsl(144 51% 13%);
  border-color: oklch(0.282 0.054 154.3);
}

Tailwind CSS v4

@theme {
  --color-pitch-black-forests: #10311d;
  --color-pitch-black-forests-50: #eafaef;
  --color-pitch-black-forests-100: #daeee1;
  --color-pitch-black-forests-200: #c3dccb;
  --color-pitch-black-forests-300: #a2c0ac;
  --color-pitch-black-forests-400: #86a890;
  --color-pitch-black-forests-500: #6a9176;
  --color-pitch-black-forests-600: #5a7b64;
  --color-pitch-black-forests-700: #486250;
  --color-pitch-black-forests-800: #344839;
  --color-pitch-black-forests-900: #243227;
  --color-pitch-black-forests-950: #121e15;
}

SCSS

$pitch-black-forests: #10311d;
$pitch-black-forests-rgb: 16, 49, 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);
}