#63994A

CSS

:root {
  --bitter-leaf: #63994a;
  --bitter-leaf-rgb: 99 153 74;
  --bitter-leaf-oklch: oklch(0.626 0.125 136.6);
}

.element {
  color: var(--bitter-leaf);
  background-color: hsl(101 35% 45%);
  border-color: oklch(0.626 0.125 136.6);
}

Tailwind CSS v4

@theme {
  --color-bitter-leaf: #63994a;
  --color-bitter-leaf-50: #e4fedc;
  --color-bitter-leaf-100: #d4f3cb;
  --color-bitter-leaf-200: #bae2ae;
  --color-bitter-leaf-300: #97c789;
  --color-bitter-leaf-400: #7baf64;
  --color-bitter-leaf-500: #5d9840;
  --color-bitter-leaf-600: #4f8137;
  --color-bitter-leaf-700: #3f672c;
  --color-bitter-leaf-800: #2f4c1c;
  --color-bitter-leaf-900: #203412;
  --color-bitter-leaf-950: #0f2005;
}

SCSS

$bitter-leaf: #63994a;
$bitter-leaf-rgb: 99, 153, 74;
$bitter-leaf-light: mix(#fff, $bitter-leaf, 20%);
$bitter-leaf-dark: mix(#000, $bitter-leaf, 20%);

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