#5E706C

CSS

:root {
  --dark-forest: #5e706c;
  --dark-forest-rgb: 94 112 108;
  --dark-forest-oklch: oklch(0.529 0.022 180.5);
}

.element {
  color: var(--dark-forest);
  background-color: hsl(167 9% 40%);
  border-color: oklch(0.529 0.022 180.5);
}

Tailwind CSS v4

@theme {
  --color-dark-forest: #5e706c;
  --color-dark-forest-50: #eff7f5;
  --color-dark-forest-100: #e0eae8;
  --color-dark-forest-200: #cad7d5;
  --color-dark-forest-300: #acbbb8;
  --color-dark-forest-400: #91a39f;
  --color-dark-forest-500: #778b87;
  --color-dark-forest-600: #657672;
  --color-dark-forest-700: #505e5b;
  --color-dark-forest-800: #3a4542;
  --color-dark-forest-900: #28302e;
  --color-dark-forest-950: #161c1b;
}

SCSS

$dark-forest: #5e706c;
$dark-forest-rgb: 94, 112, 108;
$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);
}