#567C74

CSS

:root {
  --turquoise-tortoise: #567c74;
  --turquoise-tortoise-rgb: 86 124 116;
  --turquoise-tortoise-oklch: oklch(0.555 0.045 180);
}

.element {
  color: var(--turquoise-tortoise);
  background-color: hsl(167 18% 41%);
  border-color: oklch(0.555 0.045 180);
}

Tailwind CSS v4

@theme {
  --color-turquoise-tortoise: #567c74;
  --color-turquoise-tortoise-50: #e8faf6;
  --color-turquoise-tortoise-100: #d9ede9;
  --color-turquoise-tortoise-200: #c1dbd5;
  --color-turquoise-tortoise-300: #9fbfb9;
  --color-turquoise-tortoise-400: #82a79f;
  --color-turquoise-tortoise-500: #659087;
  --color-turquoise-tortoise-600: #567a72;
  --color-turquoise-tortoise-700: #45625b;
  --color-turquoise-tortoise-800: #324842;
  --color-turquoise-tortoise-900: #22322e;
  --color-turquoise-tortoise-950: #111e1b;
}

SCSS

$turquoise-tortoise: #567c74;
$turquoise-tortoise-rgb: 86, 124, 116;
$turquoise-tortoise-light: mix(#fff, $turquoise-tortoise, 20%);
$turquoise-tortoise-dark: mix(#000, $turquoise-tortoise, 20%);

.element {
  color: $turquoise-tortoise;
  box-shadow: 0 0 0 2px rgba($turquoise-tortoise, 0.35);
}