#57AE1F

CSS

:root {
  --grass: #57ae1f;
  --grass-rgb: 87 174 31;
  --grass-oklch: oklch(0.67 0.189 136.6);
}

.element {
  color: var(--grass);
  background-color: hsl(97 70% 40%);
  border-color: oklch(0.67 0.189 136.6);
}

Tailwind CSS v4

@theme {
  --color-grass: #57ae1f;
  --color-grass-50: #daffcf;
  --color-grass-100: #c8f8ba;
  --color-grass-200: #abe898;
  --color-grass-300: #83ce6c;
  --color-grass-400: #64b737;
  --color-grass-500: #3da000;
  --color-grass-600: #358700;
  --color-grass-700: #2a6c00;
  --color-grass-800: #224f00;
  --color-grass-900: #163700;
  --color-grass-950: #072200;
}

SCSS

$grass: #57ae1f;
$grass-rgb: 87, 174, 31;
$grass-light: mix(#fff, $grass, 20%);
$grass-dark: mix(#000, $grass, 20%);

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