#517E7B

CSS

:root {
  --turquoise-tortoise: #517e7b;
  --turquoise-tortoise-rgb: 81 126 123;
  --turquoise-tortoise-oklch: oklch(0.56 0.05 190.5);
}

.element {
  color: var(--turquoise-tortoise);
  background-color: hsl(176 22% 41%);
  border-color: oklch(0.56 0.05 190.5);
}

Tailwind CSS v4

@theme {
  --color-turquoise-tortoise: #517e7b;
  --color-turquoise-tortoise-50: #e6faf9;
  --color-turquoise-tortoise-100: #d6eeec;
  --color-turquoise-tortoise-200: #bddbda;
  --color-turquoise-tortoise-300: #9bc0be;
  --color-turquoise-tortoise-400: #7da8a5;
  --color-turquoise-tortoise-500: #5e918e;
  --color-turquoise-tortoise-600: #507b78;
  --color-turquoise-tortoise-700: #406260;
  --color-turquoise-tortoise-800: #2e4846;
  --color-turquoise-tortoise-900: #1f3230;
  --color-turquoise-tortoise-950: #0f1e1c;
}

SCSS

$turquoise-tortoise: #517e7b;
$turquoise-tortoise-rgb: 81, 126, 123;
$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);
}