#1B4827

CSS

:root {
  --queen-of-trees: #1b4827;
  --queen-of-trees-rgb: 27 72 39;
  --queen-of-trees-oklch: oklch(0.361 0.075 149.8);
}

.element {
  color: var(--queen-of-trees);
  background-color: hsl(136 45% 19%);
  border-color: oklch(0.361 0.075 149.8);
}

Tailwind CSS v4

@theme {
  --color-queen-of-trees: #1b4827;
  --color-queen-of-trees-50: #e6fceb;
  --color-queen-of-trees-100: #d6f0dc;
  --color-queen-of-trees-200: #bddec5;
  --color-queen-of-trees-300: #9bc3a5;
  --color-queen-of-trees-400: #7fab87;
  --color-queen-of-trees-500: #61946b;
  --color-queen-of-trees-600: #537e5b;
  --color-queen-of-trees-700: #426449;
  --color-queen-of-trees-800: #304a33;
  --color-queen-of-trees-900: #213323;
  --color-queen-of-trees-950: #101f12;
}

SCSS

$queen-of-trees: #1b4827;
$queen-of-trees-rgb: 27, 72, 39;
$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);
}