#3C7F79

CSS

:root {
  --turquoise-tortoise: #3c7f79;
  --turquoise-tortoise-rgb: 60 127 121;
  --turquoise-tortoise-oklch: oklch(0.551 0.069 187.6);
}

.element {
  color: var(--turquoise-tortoise);
  background-color: hsl(175 36% 37%);
  border-color: oklch(0.551 0.069 187.6);
}

Tailwind CSS v4

@theme {
  --color-turquoise-tortoise: #3c7f79;
  --color-turquoise-tortoise-50: #e0fcf9;
  --color-turquoise-tortoise-100: #cff0ed;
  --color-turquoise-tortoise-200: #b4deda;
  --color-turquoise-tortoise-300: #8fc3bf;
  --color-turquoise-tortoise-400: #6daca6;
  --color-turquoise-tortoise-500: #4a958e;
  --color-turquoise-tortoise-600: #407e78;
  --color-turquoise-tortoise-700: #336560;
  --color-turquoise-tortoise-800: #244a46;
  --color-turquoise-tortoise-900: #183330;
  --color-turquoise-tortoise-950: #081f1c;
}

SCSS

$turquoise-tortoise: #3c7f79;
$turquoise-tortoise-rgb: 60, 127, 121;
$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);
}