#427E7C

CSS

:root {
  --turquoise-tortoise: #427e7c;
  --turquoise-tortoise-rgb: 66 126 124;
  --turquoise-tortoise-oklch: oklch(0.552 0.063 192.7);
}

.element {
  color: var(--turquoise-tortoise);
  background-color: hsl(178 31% 38%);
  border-color: oklch(0.552 0.063 192.7);
}

Tailwind CSS v4

@theme {
  --color-turquoise-tortoise: #427e7c;
  --color-turquoise-tortoise-50: #e2fbfa;
  --color-turquoise-tortoise-100: #d1efee;
  --color-turquoise-tortoise-200: #b6dddc;
  --color-turquoise-tortoise-300: #92c2c1;
  --color-turquoise-tortoise-400: #72aba8;
  --color-turquoise-tortoise-500: #509491;
  --color-turquoise-tortoise-600: #457d7b;
  --color-turquoise-tortoise-700: #376462;
  --color-turquoise-tortoise-800: #274947;
  --color-turquoise-tortoise-900: #1a3331;
  --color-turquoise-tortoise-950: #0a1f1d;
}

SCSS

$turquoise-tortoise: #427e7c;
$turquoise-tortoise-rgb: 66, 126, 124;
$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);
}