#4C6258

CSS

:root {
  --dark-forest: #4c6258;
  --dark-forest-rgb: 76 98 88;
  --dark-forest-oklch: oklch(0.475 0.031 165.6);
}

.element {
  color: var(--dark-forest);
  background-color: hsl(153 13% 34%);
  border-color: oklch(0.475 0.031 165.6);
}

Tailwind CSS v4

@theme {
  --color-dark-forest: #4c6258;
  --color-dark-forest-50: #edf8f3;
  --color-dark-forest-100: #dfebe6;
  --color-dark-forest-200: #c8d9d1;
  --color-dark-forest-300: #a9bdb4;
  --color-dark-forest-400: #8ea59a;
  --color-dark-forest-500: #738d81;
  --color-dark-forest-600: #62776d;
  --color-dark-forest-700: #4e5f57;
  --color-dark-forest-800: #39463f;
  --color-dark-forest-900: #27302c;
  --color-dark-forest-950: #151d19;
}

SCSS

$dark-forest: #4c6258;
$dark-forest-rgb: 76, 98, 88;
$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);
}