#556E69

CSS

:root {
  --dark-forest: #556e69;
  --dark-forest-rgb: 85 110 105;
  --dark-forest-oklch: oklch(0.517 0.031 181.5);
}

.element {
  color: var(--dark-forest);
  background-color: hsl(168 13% 38%);
  border-color: oklch(0.517 0.031 181.5);
}

Tailwind CSS v4

@theme {
  --color-dark-forest: #556e69;
  --color-dark-forest-50: #ecf8f6;
  --color-dark-forest-100: #ddebe9;
  --color-dark-forest-200: #c7d9d5;
  --color-dark-forest-300: #a7bdb9;
  --color-dark-forest-400: #8ca59f;
  --color-dark-forest-500: #718d87;
  --color-dark-forest-600: #5f7773;
  --color-dark-forest-700: #4c605c;
  --color-dark-forest-800: #374643;
  --color-dark-forest-900: #26302e;
  --color-dark-forest-950: #141d1b;
}

SCSS

$dark-forest: #556e69;
$dark-forest-rgb: 85, 110, 105;
$dark-forest-light: mix(#fff, $dark-forest, 20%);
$dark-forest-dark: mix(#000, $dark-forest, 20%);

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