#677A77

CSS

:root {
  --underwater-world: #677a77;
  --underwater-world-rgb: 103 122 119;
  --underwater-world-oklch: oklch(0.563 0.023 185);
}

.element {
  color: var(--underwater-world);
  background-color: hsl(171 8% 44%);
  border-color: oklch(0.563 0.023 185);
}

Tailwind CSS v4

@theme {
  --color-underwater-world: #677a77;
  --color-underwater-world-50: #eef7f6;
  --color-underwater-world-100: #e0eae9;
  --color-underwater-world-200: #cad8d6;
  --color-underwater-world-300: #abbbb9;
  --color-underwater-world-400: #90a3a0;
  --color-underwater-world-500: #768b88;
  --color-underwater-world-600: #647673;
  --color-underwater-world-700: #505e5c;
  --color-underwater-world-800: #3a4543;
  --color-underwater-world-900: #28302e;
  --color-underwater-world-950: #161c1b;
}

SCSS

$underwater-world: #677a77;
$underwater-world-rgb: 103, 122, 119;
$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);
}