#143C1F

CSS

:root {
  --queen-of-trees: #143c1f;
  --queen-of-trees-rgb: 20 60 31;
  --queen-of-trees-oklch: oklch(0.319 0.068 149.9);
}

.element {
  color: var(--queen-of-trees);
  background-color: hsl(137 50% 16%);
  border-color: oklch(0.319 0.068 149.9);
}

Tailwind CSS v4

@theme {
  --color-queen-of-trees: #143c1f;
  --color-queen-of-trees-50: #e8fbec;
  --color-queen-of-trees-100: #d8efdd;
  --color-queen-of-trees-200: #c0ddc6;
  --color-queen-of-trees-300: #9ec2a6;
  --color-queen-of-trees-400: #82aa89;
  --color-queen-of-trees-500: #65936e;
  --color-queen-of-trees-600: #567c5d;
  --color-queen-of-trees-700: #44644a;
  --color-queen-of-trees-800: #324935;
  --color-queen-of-trees-900: #223324;
  --color-queen-of-trees-950: #111e13;
}

SCSS

$queen-of-trees: #143c1f;
$queen-of-trees-rgb: 20, 60, 31;
$queen-of-trees-light: mix(#fff, $queen-of-trees, 20%);
$queen-of-trees-dark: mix(#000, $queen-of-trees, 20%);

.element {
  color: $queen-of-trees;
  box-shadow: 0 0 0 2px rgba($queen-of-trees, 0.35);
}