#3B7F7A

CSS

:root {
  --turquoise-tortoise: #3b7f7a;
  --turquoise-tortoise-rgb: 59 127 122;
  --turquoise-tortoise-oklch: oklch(0.551 0.069 188.9);
}

.element {
  color: var(--turquoise-tortoise);
  background-color: hsl(176 37% 36%);
  border-color: oklch(0.551 0.069 188.9);
}

Tailwind CSS v4

@theme {
  --color-turquoise-tortoise: #3b7f7a;
  --color-turquoise-tortoise-50: #e0fcfa;
  --color-turquoise-tortoise-100: #cff0ed;
  --color-turquoise-tortoise-200: #b3dedb;
  --color-turquoise-tortoise-300: #8ec3c0;
  --color-turquoise-tortoise-400: #6caca7;
  --color-turquoise-tortoise-500: #49958f;
  --color-turquoise-tortoise-600: #3f7e79;
  --color-turquoise-tortoise-700: #326561;
  --color-turquoise-tortoise-800: #234a46;
  --color-turquoise-tortoise-900: #173431;
  --color-turquoise-tortoise-950: #081f1d;
}

SCSS

$turquoise-tortoise: #3b7f7a;
$turquoise-tortoise-rgb: 59, 127, 122;
$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);
}