#517F73

CSS

:root {
  --turquoise-tortoise: #517f73;
  --turquoise-tortoise-rgb: 81 127 115;
  --turquoise-tortoise-oklch: oklch(0.56 0.054 176);
}

.element {
  color: var(--turquoise-tortoise);
  background-color: hsl(164 22% 41%);
  border-color: oklch(0.56 0.054 176);
}

Tailwind CSS v4

@theme {
  --color-turquoise-tortoise: #517f73;
  --color-turquoise-tortoise-50: #e6fbf5;
  --color-turquoise-tortoise-100: #d6eee8;
  --color-turquoise-tortoise-200: #bddcd4;
  --color-turquoise-tortoise-300: #9bc1b7;
  --color-turquoise-tortoise-400: #7da99d;
  --color-turquoise-tortoise-500: #5e9285;
  --color-turquoise-tortoise-600: #507c70;
  --color-turquoise-tortoise-700: #40635a;
  --color-turquoise-tortoise-800: #2e4941;
  --color-turquoise-tortoise-900: #1f322d;
  --color-turquoise-tortoise-950: #0f1e1a;
}

SCSS

$turquoise-tortoise: #517f73;
$turquoise-tortoise-rgb: 81, 127, 115;
$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);
}