#617C78

CSS

:root {
  --underwater-world: #617c78;
  --underwater-world-rgb: 97 124 120;
  --underwater-world-oklch: oklch(0.564 0.032 185.2);
}

.element {
  color: var(--underwater-world);
  background-color: hsl(171 12% 43%);
  border-color: oklch(0.564 0.032 185.2);
}

Tailwind CSS v4

@theme {
  --color-underwater-world: #617c78;
  --color-underwater-world-50: #ecf8f7;
  --color-underwater-world-100: #ddecea;
  --color-underwater-world-200: #c6d9d6;
  --color-underwater-world-300: #a6bdba;
  --color-underwater-world-400: #8aa5a1;
  --color-underwater-world-500: #6f8d89;
  --color-underwater-world-600: #5e7874;
  --color-underwater-world-700: #4b605d;
  --color-underwater-world-800: #364643;
  --color-underwater-world-900: #25312f;
  --color-underwater-world-950: #141d1b;
}

SCSS

$underwater-world: #617c78;
$underwater-world-rgb: 97, 124, 120;
$underwater-world-light: mix(#fff, $underwater-world, 20%);
$underwater-world-dark: mix(#000, $underwater-world, 20%);

.element {
  color: $underwater-world;
  box-shadow: 0 0 0 2px rgba($underwater-world, 0.35);
}