#1A4900

CSS

:root {
  --woodland-grass: #1a4900;
  --woodland-grass-rgb: 26 73 0;
  --woodland-grass-oklch: oklch(0.358 0.11 137.8);
}

.element {
  color: var(--woodland-grass);
  background-color: hsl(99 100% 14%);
  border-color: oklch(0.358 0.11 137.8);
}

Tailwind CSS v4

@theme {
  --color-woodland-grass: #1a4900;
  --color-woodland-grass-50: #e5fee0;
  --color-woodland-grass-100: #d5f2cf;
  --color-woodland-grass-200: #bce0b4;
  --color-woodland-grass-300: #9ac690;
  --color-woodland-grass-400: #7eae6d;
  --color-woodland-grass-500: #60974c;
  --color-woodland-grass-600: #528041;
  --color-woodland-grass-700: #416634;
  --color-woodland-grass-800: #304b23;
  --color-woodland-grass-900: #213417;
  --color-woodland-grass-950: #101f08;
}

SCSS

$woodland-grass: #1a4900;
$woodland-grass-rgb: 26, 73, 0;
$woodland-grass-light: mix(#fff, $woodland-grass, 20%);
$woodland-grass-dark: mix(#000, $woodland-grass, 20%);

.element {
  color: $woodland-grass;
  box-shadow: 0 0 0 2px rgba($woodland-grass, 0.35);
}