#5AAD40

CSS

:root {
  --grass: #5aad40;
  --grass-rgb: 90 173 64;
  --grass-oklch: oklch(0.672 0.167 139);
}

.element {
  color: var(--grass);
  background-color: hsl(106 46% 46%);
  border-color: oklch(0.672 0.167 139);
}

Tailwind CSS v4

@theme {
  --color-grass: #5aad40;
  --color-grass-50: #dcffd5;
  --color-grass-100: #caf6c2;
  --color-grass-200: #ade6a3;
  --color-grass-300: #86cc7b;
  --color-grass-400: #67b54f;
  --color-grass-500: #419e1c;
  --color-grass-600: #38861b;
  --color-grass-700: #2d6b16;
  --color-grass-800: #234f08;
  --color-grass-900: #173706;
  --color-grass-950: #082100;
}

SCSS

$grass: #5aad40;
$grass-rgb: 90, 173, 64;
$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);
}