#657225

CSS

:root {
  --muddy-green: #657225;
  --muddy-green-rgb: 101 114 37;
  --muddy-green-oklch: oklch(0.525 0.102 118.2);
}

.element {
  color: var(--muddy-green);
  background-color: hsl(70 51% 30%);
  border-color: oklch(0.525 0.102 118.2);
}

Tailwind CSS v4

@theme {
  --color-muddy-green: #657225;
  --color-muddy-green-50: #f1fada;
  --color-muddy-green-100: #e3eec8;
  --color-muddy-green-200: #cedbab;
  --color-muddy-green-300: #b0c084;
  --color-muddy-green-400: #99a75f;
  --color-muddy-green-500: #808f3a;
  --color-muddy-green-600: #6c7932;
  --color-muddy-green-700: #576128;
  --color-muddy-green-800: #40471a;
  --color-muddy-green-900: #2c3111;
  --color-muddy-green-950: #1a1d04;
}

SCSS

$muddy-green: #657225;
$muddy-green-rgb: 101, 114, 37;
$muddy-green-light: mix(#fff, $muddy-green, 20%);
$muddy-green-dark: mix(#000, $muddy-green, 20%);

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