#587267

CSS

:root {
  --dark-forest: #587267;
  --dark-forest-rgb: 88 114 103;
  --dark-forest-oklch: oklch(0.528 0.035 167.3);
}

.element {
  color: var(--dark-forest);
  background-color: hsl(155 13% 40%);
  border-color: oklch(0.528 0.035 167.3);
}

Tailwind CSS v4

@theme {
  --color-dark-forest: #587267;
  --color-dark-forest-50: #ecf9f3;
  --color-dark-forest-100: #ddece6;
  --color-dark-forest-200: #c7d9d2;
  --color-dark-forest-300: #a7bdb4;
  --color-dark-forest-400: #8ba59a;
  --color-dark-forest-500: #708e81;
  --color-dark-forest-600: #5f786e;
  --color-dark-forest-700: #4c6058;
  --color-dark-forest-800: #37463f;
  --color-dark-forest-900: #26312c;
  --color-dark-forest-950: #141d19;
}

SCSS

$dark-forest: #587267;
$dark-forest-rgb: 88, 114, 103;
$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);
}