#1F4828

CSS

:root {
  --queen-of-trees: #1f4828;
  --queen-of-trees-rgb: 31 72 40;
  --queen-of-trees-oklch: oklch(0.363 0.072 148.9);
}

.element {
  color: var(--queen-of-trees);
  background-color: hsl(133 40% 20%);
  border-color: oklch(0.363 0.072 148.9);
}

Tailwind CSS v4

@theme {
  --color-queen-of-trees: #1f4828;
  --color-queen-of-trees-50: #e7fbeb;
  --color-queen-of-trees-100: #d8efdc;
  --color-queen-of-trees-200: #bfddc5;
  --color-queen-of-trees-300: #9dc2a5;
  --color-queen-of-trees-400: #81ab87;
  --color-queen-of-trees-500: #64946c;
  --color-queen-of-trees-600: #557d5c;
  --color-queen-of-trees-700: #446449;
  --color-queen-of-trees-800: #324934;
  --color-queen-of-trees-900: #223323;
  --color-queen-of-trees-950: #111e12;
}

SCSS

$queen-of-trees: #1f4828;
$queen-of-trees-rgb: 31, 72, 40;
$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);
}