#5E7066

CSS

:root {
  --dark-forest: #5e7066;
  --dark-forest-rgb: 94 112 102;
  --dark-forest-oklch: oklch(0.527 0.027 161);
}

.element {
  color: var(--dark-forest);
  background-color: hsl(147 9% 40%);
  border-color: oklch(0.527 0.027 161);
}

Tailwind CSS v4

@theme {
  --color-dark-forest: #5e7066;
  --color-dark-forest-50: #eff8f3;
  --color-dark-forest-100: #e0ebe5;
  --color-dark-forest-200: #cbd8d1;
  --color-dark-forest-300: #acbcb3;
  --color-dark-forest-400: #91a499;
  --color-dark-forest-500: #778c80;
  --color-dark-forest-600: #65766d;
  --color-dark-forest-700: #515f57;
  --color-dark-forest-800: #3b453f;
  --color-dark-forest-900: #28302b;
  --color-dark-forest-950: #161c19;
}

SCSS

$dark-forest: #5e7066;
$dark-forest-rgb: 94, 112, 102;
$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);
}