#51806E

CSS

:root {
  --turquoise-tortoise: #51806e;
  --turquoise-tortoise-rgb: 81 128 110;
  --turquoise-tortoise-oklch: oklch(0.56 0.059 168.1);
}

.element {
  color: var(--turquoise-tortoise);
  background-color: hsl(157 22% 41%);
  border-color: oklch(0.56 0.059 168.1);
}

Tailwind CSS v4

@theme {
  --color-turquoise-tortoise: #51806e;
  --color-turquoise-tortoise-50: #e6fbf2;
  --color-turquoise-tortoise-100: #d6efe5;
  --color-turquoise-tortoise-200: #bcddd0;
  --color-turquoise-tortoise-300: #9ac2b3;
  --color-turquoise-tortoise-400: #7caa98;
  --color-turquoise-tortoise-500: #5e937f;
  --color-turquoise-tortoise-600: #507c6b;
  --color-turquoise-tortoise-700: #406456;
  --color-turquoise-tortoise-800: #2e493e;
  --color-turquoise-tortoise-900: #1f332a;
  --color-turquoise-tortoise-950: #0f1e18;
}

SCSS

$turquoise-tortoise: #51806e;
$turquoise-tortoise-rgb: 81, 128, 110;
$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);
}