#437F79

CSS

:root {
  --turquoise-tortoise: #437f79;
  --turquoise-tortoise-rgb: 67 127 121;
  --turquoise-tortoise-oklch: oklch(0.554 0.064 187.1);
}

.element {
  color: var(--turquoise-tortoise);
  background-color: hsl(174 31% 38%);
  border-color: oklch(0.554 0.064 187.1);
}

Tailwind CSS v4

@theme {
  --color-turquoise-tortoise: #437f79;
  --color-turquoise-tortoise-50: #e2fbf9;
  --color-turquoise-tortoise-100: #d1efec;
  --color-turquoise-tortoise-200: #b6ddda;
  --color-turquoise-tortoise-300: #92c2be;
  --color-turquoise-tortoise-400: #72aba5;
  --color-turquoise-tortoise-500: #50948d;
  --color-turquoise-tortoise-600: #457d77;
  --color-turquoise-tortoise-700: #376460;
  --color-turquoise-tortoise-800: #274a45;
  --color-turquoise-tortoise-900: #1a3330;
  --color-turquoise-tortoise-950: #0a1f1c;
}

SCSS

$turquoise-tortoise: #437f79;
$turquoise-tortoise-rgb: 67, 127, 121;
$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);
}