#397F7C

CSS

:root {
  --turquoise-tortoise: #397f7c;
  --turquoise-tortoise-rgb: 57 127 124;
  --turquoise-tortoise-oklch: oklch(0.551 0.07 191.5);
}

.element {
  color: var(--turquoise-tortoise);
  background-color: hsl(177 38% 36%);
  border-color: oklch(0.551 0.07 191.5);
}

Tailwind CSS v4

@theme {
  --color-turquoise-tortoise: #397f7c;
  --color-turquoise-tortoise-50: #dffcfb;
  --color-turquoise-tortoise-100: #cef0ee;
  --color-turquoise-tortoise-200: #b2dedd;
  --color-turquoise-tortoise-300: #8dc3c2;
  --color-turquoise-tortoise-400: #6baca9;
  --color-turquoise-tortoise-500: #479592;
  --color-turquoise-tortoise-600: #3d7e7b;
  --color-turquoise-tortoise-700: #306563;
  --color-turquoise-tortoise-800: #224a47;
  --color-turquoise-tortoise-900: #173432;
  --color-turquoise-tortoise-950: #071f1e;
}

SCSS

$turquoise-tortoise: #397f7c;
$turquoise-tortoise-rgb: 57, 127, 124;
$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);
}