#003B00

CSS

:root {
  --woodland-grass: #003b00;
  --woodland-grass-rgb: 0 59 0;
  --woodland-grass-oklch: oklch(0.305 0.104 142.5);
}

.element {
  color: var(--woodland-grass);
  background-color: hsl(120 100% 12%);
  border-color: oklch(0.305 0.104 142.5);
}

Tailwind CSS v4

@theme {
  --color-woodland-grass: #003b00;
  --color-woodland-grass-50: #e4fee3;
  --color-woodland-grass-100: #d4f2d3;
  --color-woodland-grass-200: #bae1b9;
  --color-woodland-grass-300: #97c696;
  --color-woodland-grass-400: #7aae75;
  --color-woodland-grass-500: #5b9756;
  --color-woodland-grass-600: #4e804a;
  --color-woodland-grass-700: #3e673a;
  --color-woodland-grass-800: #2e4b28;
  --color-woodland-grass-900: #1f341b;
  --color-woodland-grass-950: #0e200b;
}

SCSS

$woodland-grass: #003b00;
$woodland-grass-rgb: 0, 59, 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);
}