#447E78

CSS

:root {
  --turquoise-tortoise: #447e78;
  --turquoise-tortoise-rgb: 68 126 120;
  --turquoise-tortoise-oklch: oklch(0.552 0.062 186.9);
}

.element {
  color: var(--turquoise-tortoise);
  background-color: hsl(174 30% 38%);
  border-color: oklch(0.552 0.062 186.9);
}

Tailwind CSS v4

@theme {
  --color-turquoise-tortoise: #447e78;
  --color-turquoise-tortoise-50: #e2fbf9;
  --color-turquoise-tortoise-100: #d2efec;
  --color-turquoise-tortoise-200: #b7ddd9;
  --color-turquoise-tortoise-300: #93c2be;
  --color-turquoise-tortoise-400: #73aba4;
  --color-turquoise-tortoise-500: #52948d;
  --color-turquoise-tortoise-600: #477d77;
  --color-turquoise-tortoise-700: #38645f;
  --color-turquoise-tortoise-800: #284945;
  --color-turquoise-tortoise-900: #1b3330;
  --color-turquoise-tortoise-950: #0b1f1c;
}

SCSS

$turquoise-tortoise: #447e78;
$turquoise-tortoise-rgb: 68, 126, 120;
$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);
}