#5D7069

CSS

:root {
  --dark-forest: #5d7069;
  --dark-forest-rgb: 93 112 105;
  --dark-forest-oklch: oklch(0.527 0.025 171);
}

.element {
  color: var(--dark-forest);
  background-color: hsl(158 9% 40%);
  border-color: oklch(0.527 0.025 171);
}

Tailwind CSS v4

@theme {
  --color-dark-forest: #5d7069;
  --color-dark-forest-50: #eef8f4;
  --color-dark-forest-100: #e0ebe7;
  --color-dark-forest-200: #cad8d3;
  --color-dark-forest-300: #abbcb6;
  --color-dark-forest-400: #90a49c;
  --color-dark-forest-500: #768c84;
  --color-dark-forest-600: #647670;
  --color-dark-forest-700: #505f59;
  --color-dark-forest-800: #3a4541;
  --color-dark-forest-900: #28302d;
  --color-dark-forest-950: #161c1a;
}

SCSS

$dark-forest: #5d7069;
$dark-forest-rgb: 93, 112, 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);
}