#637E4B

CSS

:root {
  --beyond-the-pines: #637e4b;
  --beyond-the-pines-rgb: 99 126 75;
  --beyond-the-pines-oklch: oklch(0.559 0.081 131.3);
}

.element {
  color: var(--beyond-the-pines);
  background-color: hsl(92 25% 39%);
  border-color: oklch(0.559 0.081 131.3);
}

Tailwind CSS v4

@theme {
  --color-beyond-the-pines: #637e4b;
  --color-beyond-the-pines-50: #ecfbe3;
  --color-beyond-the-pines-100: #ddeed3;
  --color-beyond-the-pines-200: #c7dcb9;
  --color-beyond-the-pines-300: #a7c197;
  --color-beyond-the-pines-400: #8da976;
  --color-beyond-the-pines-500: #739158;
  --color-beyond-the-pines-600: #617b4b;
  --color-beyond-the-pines-700: #4e623c;
  --color-beyond-the-pines-800: #394829;
  --color-beyond-the-pines-900: #27321c;
  --color-beyond-the-pines-950: #151e0c;
}

SCSS

$beyond-the-pines: #637e4b;
$beyond-the-pines-rgb: 99, 126, 75;
$beyond-the-pines-light: mix(#fff, $beyond-the-pines, 20%);
$beyond-the-pines-dark: mix(#000, $beyond-the-pines, 20%);

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