#577C71

CSS

:root {
  --turquoise-tortoise: #577c71;
  --turquoise-tortoise-rgb: 87 124 113;
  --turquoise-tortoise-oklch: oklch(0.555 0.045 174.2);
}

.element {
  color: var(--turquoise-tortoise);
  background-color: hsl(162 18% 41%);
  border-color: oklch(0.555 0.045 174.2);
}

Tailwind CSS v4

@theme {
  --color-turquoise-tortoise: #577c71;
  --color-turquoise-tortoise-50: #e9faf5;
  --color-turquoise-tortoise-100: #d9ede7;
  --color-turquoise-tortoise-200: #c1dbd3;
  --color-turquoise-tortoise-300: #a0bfb6;
  --color-turquoise-tortoise-400: #83a89c;
  --color-turquoise-tortoise-500: #679084;
  --color-turquoise-tortoise-600: #577a70;
  --color-turquoise-tortoise-700: #456259;
  --color-turquoise-tortoise-800: #324841;
  --color-turquoise-tortoise-900: #22322c;
  --color-turquoise-tortoise-950: #111e1a;
}

SCSS

$turquoise-tortoise: #577c71;
$turquoise-tortoise-rgb: 87, 124, 113;
$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);
}